The present application refers to photoinitiator compounds comprising addition fragmentation agent (AFA) type chain transfer groups, macrophotoinitiators, which are obtained by the polymerization of monomers in the presence of photoinitiators with said chain transfer groups and the photopolymerization of said macrophotoinitiators to give block copolymers.
In European Patent Application No. 98810501.1, filed May 29, 1998 photoinitiator compounds comprising SH-substitutents as chain transfer agents are disclosed. Y. Yagci et al in J. Macromol. Sci. Chem., A28(1), pp. 129-141 (1991) describe the use of azo-benzoin compounds as initiators for the preparation of block-copolymers, thermally polymerizing the first monomer with the compounds and then polymerizing the second monomer photochemically. In J. of Polym. Sci., Part A, Polymer Chemistry, Vol. 34, 3471-3484 (1996) and FR-A 2715653 R. Popielarz employs compounds having thermal chain transferring moieties and thermal initiating moieties for the preparation of block-copolymers. Some odorless functional copolymers by using AFA type chain transfer agents are disclosed for examples in WO 88/4304, WO 91/7387, WO 91/7440 and U.S. Pat. No. 5,395,903.
In technique, there still exists a need for reactive, easy to prepare, easy to handle and odorless photoinitiator compounds and there is a need for easy controllable preparation methods for defined block copolymers. By means of photopolymerization with specific macrophotoinitiators such copolymers are obtainable.
Subject of the invention therefore are odorless photoinitiator compounds having chain transfer groups. The compounds comprising chain transfer groups are those of formula Ia or Ib 
wherein
n is 1 or 2;
PI is a group of formula IIa, IIb or IIc 
PIxe2x80x2 is a group of formula IIIa or IIIb 
Ar is phenyl, biphenylyl or benzoylphenyl, each of which is unsubstituted or substituted 1 to 5 times by halogen, C1-C12alkyl, C3-C12alkenyl, C5-C6cycloalkyl, phenyl-C1-C3alkyl, xe2x80x94COOH, xe2x80x94COO(C1-C4alkyl), xe2x80x94OR7, xe2x80x94SR8, xe2x80x94SOR8, xe2x80x94SO2R8, xe2x80x94CN, xe2x80x94SO2NH2, xe2x80x94SO2NH(C1-C4alkyl), xe2x80x94SO2xe2x80x94N(C1-C4alkyl)2, xe2x80x94NR9R10, xe2x80x94NHCOR9, or by a group of formula IV, 
or Ar is a group of formula V or VI 
Ar2 is 
xe2x80x83each of which is unsubstituted or substituted 1 to 5 times by halogen, C1-C12alkyl, C3-C12alkenyl, C5-C6cycloalkyl, phenyl-C1-C3alkyl, xe2x80x94COOH, xe2x80x94COO(C1-C4alkyl), xe2x80x94OR7, xe2x80x94SR8, xe2x80x94SOR8, xe2x80x94SO2R8, xe2x80x94CN, xe2x80x94SO2NH2, xe2x80x94SO2NH(C1-C4alkyl), xe2x80x94SO2xe2x80x94N(C1-C4alkyl)2, xe2x80x94NR9R10, xe2x80x94NHCOR9, or by a group of formula IV;
or Ar2 is a group of formula Va or VIa 
G is unbranched or branched C1-C7alkylene;
L and E independently of one another are a direct bond, 13 Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94, provided that L and E are not both a direct bond simultaneously;
R1 and R2 independently of one another are R7Oxe2x80x94, C1-C8alkyl, which is unsubstituted or substituted by OH, C1-C4alkoxy, SR8, CN, (C1-C8alkyl)O(CO)xe2x80x94, (C1-C4alkyl)xe2x80x94(OC)Oxe2x80x94 or xe2x80x94N(R3)(R4), or R1 and R2 independently of one another are C3-C6alkenyl, phenyl, chlorophenyl, R7xe2x80x94O-phenyl, R8xe2x80x94S-phenyl or phenyl-C1-C3-alkyl, or R1 and R2 together are unbranched or branched C2-C9alkylene, C3-C9oxaalkylene or C3-C9azaalkylene, or R1 and R2 independently of one another are a radical of formula VII or VIII 
p is 0 or 1;
Ar3 is phenyl, naphthyl, furyl, thienyl or pyridiyl, each of which is unsubstituted or substituted by halogen, SH, OH, C1-C12alkyl, OH-substituted C1-C4alkyl, halogen-substituted C1-C4alkyl, SH-substituted C1-C4alkyl, N(R17)2-substituted C1-C4alkyl, C1-C12alkoxy-substituted C1-C4alkyl, (C1-C18alkyl)O(OC)-substituted C1-C4alkyl, CH3O(CH2CH2O)mCO-substituted C1-C4alkyl, (C1-C4alkyl)(OC)O-substituted C1-C4alkyl, C1-C12alkoxy, (C1-C18alkyl)(OC)O-substituted C1-C4alkoxy, CH3O(CH2CH2O)mCO-substituted C1-C4alkoxy, xe2x80x94(OCH2CH2)mOH, xe2x80x94(OCH2CH2)mOCH3, C1-C8alkylthio, phenoxy, xe2x80x94COO(C1-C18alkyl), xe2x80x94CO(OCH2CH2)mOCH3, phenyl or benzoyl;
m is 1 to 20;
M1 is xe2x80x94NR3R4 or xe2x80x94OH, or, when R1 and R2 are R7Oxe2x80x94, M1 is Ar;
M1xe2x80x2 is a group 
xe2x80x83or, when R1 and R2 are R7Oxe2x80x94, M1xe2x80x2 is Ar2;
R1xe2x80x2 and R3xe2x80x2 independently of one another are a direct bond, C1-C12alkylene, or phenylene;
E1 is xe2x80x94CH2xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94N(R6)xe2x80x94 or xe2x80x94Sxe2x80x94;
R3 is hydrogen, C1-C12alkyl, C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R3 is C3-C5alkenyl, C5-C12-cycloalkyl or phenyl-C1-C3alkyl;
R4 is C1-C12alkyl; C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R4 is C3-C5alkenyl, C5-C12-cycloalkyl, phenyl-C1-C3alkyl; phenyl which is unsubstituted or substituted by halogen, C1-C12alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl); or R4 together with R2 is C1-C7alkylene, phenyl-C1-C4alkylene, o-xylylene, 2-butenylene, C2-C3oxaalkylene or C2-C3azaalkylene;
or R3 and R4 together are C3-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94 and which C3-C7alkylene is unsubstituted or substituted by OH, SH, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl);
R6 is hydrogen, C1-C12alkyl, OH-substituted C1-C12alkyl, SH-substituted C1-C12alkyl or HSxe2x80x94(CH2)nxe2x80x94COO-substituted C1-C12alkyl; C2-C12alkyl, which is interrupted by xe2x80x94Oxe2x80x94, xe2x80x94NHxe2x80x94 or xe2x80x94Sxe2x80x94; or R6 is C3-C5alkenyl, phenyl-C1-C3-alkyl, xe2x80x94CH2CH2CN, C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, OH-substituted C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, SH-substituted C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, C2-C8alkanoyl, OH-substituted C2-C8alkanoyl, SH-substituted C2-C8alkanoyl or benzoyl;
R7 is hydrogen, C1-C12alkyl, C3-C12-alkenyl, cyclohexyl, hydroxycyclohexyl; C1-C4alkyl, which is mono- or polysubstituted by Cl, Br, CN, SH, xe2x80x94N(C1-C4alkyl)2, piperidinyl, morpholinyl, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C4alkyl)2, 
xe2x80x83xe2x80x94CO(C1-C4alkyl) or by 
xe2x80x83or R7 is 2,3-epoxypropyl, xe2x80x94(CH2CH2O)nH; phenyl which is unsubstituted or substituted by halogen, C1-C4alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl); or R7 is phenyl-C1-C3-alkyl, tetrahydropyranyl, tetrahydrofuranyl, xe2x80x94COOR19, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C8alkyl)2, xe2x80x94Si(R20)(R21)2, or xe2x80x94SO2R22;
R8 is hydrogen, C1-C12alkyl, C3-C12alkenyl, cyclohexyl, hydroxycyclohexyl; C1-C4alkyl, which is mono- or polysubstituted by Cl, Br, CN, SH, xe2x80x94N(C1-C4alkyl)2, piperidinyl, morpholinyl, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8-alkyl), xe2x80x94CON(C1-C4alkyl)2, 
xe2x80x83xe2x80x94CO(C1-C4alkyl) or 
xe2x80x83or R8 is 2,3-epoxypropyl, phenyl-C1-C3alkyl, phenyl-C1-C3hydroxyalkyl; phenyl which is unsubstituted or mono- or poly-substituted by halogen, SH, C1-C4alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl); or
R8 is 2-benzothiazyl, 2-benzimidazolyl, xe2x80x94CH2CH2xe2x80x94Oxe2x80x94CH2CH2xe2x80x94SH or xe2x80x94CH2CH2xe2x80x94Sxe2x80x94CH2CH2xe2x80x94SH;
R9 and R10 independently of one another are hydrogen, C1-C12alkyl; C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R9 and R10 independently of one another are C3-C5alkenyl, cyclohexyl, phenyl-C1-C3alkyl; phenyl which is unsubstituted or mono- or poly-substituted by C1-C12alkyl or halogen; or R9 and R10 together are C2-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
R11 and R12 independently of one another are a direct bond, xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94; provided that R11 and R12 are not a direct bond simultaneously;
R13 is hydrogen, C1-C8alkyl or phenyl;
R14, R15 and R16 independently of one another are hydrogen or C1-C4alkyl;
R17 is hydrogen, C1-C8alkyl or phenyl;
R19 is C1-C4alkyl, C2-C4alkenyl or phenyl;
R20 and R21 independently of one another are C1-C4alkyl or phenyl;
R22 is C1-C18alkyl; or phenyl which is unsubstituted or substituted by C1-C14alkyl;
A1 and A2 independently of one another are a direct bond, xe2x80x94X[(CH2)lXxe2x80x2]qxe2x80x94[(C6H4)oXxe2x80x3]rxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
X, Xxe2x80x2 and Xxe2x80x3 independently of each other are a direct bond, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94N(R6)xe2x80x94, xe2x80x94O(CO)xe2x80x94, xe2x80x94COOxe2x80x94 xe2x80x94NHCOxe2x80x94, xe2x80x94CONHxe2x80x94 or xe2x80x94COxe2x80x94;
l is an integer from 0 to 10;
q is an integer from 0 to 5:
o and r independently of one another are an integer 0, 1 or 2;
CT when n is 1, is a group of formula IXa, IXb, Xa or Xb, 
xe2x80x83or, when n is 2, CT is a group of formula XI and XII, 
Y is xe2x80x94W(R8)s;
Yxe2x80x2 is xe2x80x94W(R8)t13 R25xe2x80x94;
W is S, Si, Se, P, Br, Cl, Sn, xe2x80x94Oxe2x80x94Oxe2x80x94, S(xe2x95x90O), S(xe2x95x90O)2, or P(xe2x95x90O);
Z is xe2x80x94COOR7, xe2x80x94CONR9R10, xe2x80x94CN, or xe2x80x94Ar;
Zxe2x80x2 is xe2x80x94COOR25xe2x80x94, xe2x80x94CONR9R25xe2x80x94, or xe2x80x94Ar2xe2x80x94;
s is an integer from 0 to 3;
t is an integer 0, 1 or 2;
u is 0or 1;
R23 and R24 independently of one another are hydrogen, or C1-C8alkyl; or R23 and R24 together are C5-C7cyloalkyl; and
R25 is a direct bond, C1-C4alkylene or phenylene.
The following explanations refer to the whole context of the application.
C1-C18alkyl is linear or branched and is, for example, C1-C14-, C1-C12-, C1-C8-, C1-C6- or C1-C4alkyl. Examples are methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, 2,4,4-trimethylpentyl, 2-ethylhexyl, octyl, nonyl, decyl, dodecyl, tetradecyl, pentadecyl, hexadecyl and octadecyl.
C1-C14alkyl, C1-C12alkyl, C1-C8alkyl, C1-C6alkyl and C1-C4alkyl have the same meanings as given above for C1-C20alkyl up to the corresponding number of C-atoms.
Mono- or polysubstituted C1-C4alkyl is substituted 1 to 6 times, for example 1 to 4 times, especially once or twice.
C2-C12alkyl interrupted by 1 to 9, 1-5, 1-3 or 1 or 2xe2x80x94Oxe2x80x94, xe2x80x94N(R6)xe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94C(O)xe2x80x94, produces, for example structural units such as xe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94, xe2x80x94CH2xe2x80x94Sxe2x80x94CH2xe2x80x94, xe2x80x94CH2xe2x80x94N(CH3)xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94Oxe2x80x94CH2CH2xe2x80x94, xe2x80x94[CH2CH2O]yxe2x80x94, xe2x80x94[CH2CH2O]yxe2x80x94CH2xe2x80x94, where y=1-5, xe2x80x94(CH2CH2O)5CH2CH2xe2x80x94, xe2x80x94CH2xe2x80x94CH(CH3)xe2x80x94Oxe2x80x94CH2xe2x80x94CH(CH3)xe2x80x94 or xe2x80x94CH2xe2x80x94CH(CH3)xe2x80x94Oxe2x80x94CH2xe2x80x94CH2CH2xe2x80x94. Also the interrupted C2-C12alkyl is linear or branched.
C2-C12alkylene is linear or branched alkylene, for example C1-C9alkylene, C1-C7alkylene, C1-C6alkylene, C1-C4alkylene, namely methylene, ethylene, propylene, 1-methylethylene 1,1-dimethyl-ethylene, 2,2-dimethylpropylene, butylene, 1-methylbutylene, 1-methylpropylene, 2-methyl-propylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, dodecylene, tetradecylene or hexadecylene.
C1-C9alkylene, C1-C7alkylene and C1-C6alkylene have the same meanings as given above for C2-C16alkylene up to the corresponding number of C-atoms.
If R1 and R2 together are C2-C9alkylene, together with the C-atom to which they are bound for example propyl, pentyl, hexyl, octyl or decyl rings are produced. If R1 and R2 together are C3-C9oxaalkylene or C3-C9azaalkylene, said rings are interrupted by O or N atoms. Thus, they are, for example piperidine, azolidine, oxolane or oxane rings
If R3 and R4 together are C3-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94, together with the N-atom to which they are bound, for example morpholino or piperidino groups are formed.
If R9 and R10 together are C2-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94, together with the N-atom to which they are bound, for example morpholino or piperidino groups are formed.
C3-C12alkenyl, for example C3-C6alkenyl or C3-C5alkenyl radicals may be mono or polyunsaturated and may be linear or branched and are for example allyl, methallyl, 1,1-dimethylallyl, 1-butenyl, 3-butenyl, 2-butenyl, 1,3-pentadienyl, 5-hexenyl or 7-octenyl, especially allyl. C3-C6alkenyl, C3-C5alkenyl and C2-C4alkenyl have the same meanings as given above for C3-C12alkenyl up to the corresponding number of C-atoms.
C2-C8alkanoyl is for example C2-C6-, C2-C4- or C2-C3alkanoyl. These radicals are linear branched and are for example ethanoyl, propanoyl, 2-methylpropanoyl, hexanoyl or octanoyl. C2-C3alkanoyl has the same meanings as given for C2-C8alkanoyl up to the corresponding number of C-atoms.
C3-C8cycloalkyl, C5-C12cycloalkyl are for example C5-C8- or C5-C6cycloalkyl, namely cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, especially cyclopentyl and cyclohexyl, preferably cyclohexyl. C5-C6cycloalkyl is cyclopentyl or cyclohexyl.
C4-C8cycloalkenyl is, for example, C5-C6cycloalkenyl. Examples are cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, or cyclooctenyl, especially cyclopentenyl or cyclohexenyl.
C1-C12alkoxy, is for example C1-C8alkoxy, especially C1-C4alkoxy, and is a linear or branched radical, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butyloxy, sec-butyloxy, isobutyloxy, tert-butyloxy, pentyloxy, hexyloxy, heptyloxy, 2,4,4-trimethylpentyloxy, 2-ethylhexyloxy, octyloxy, nonyloxy, decyloxy or dodecyloxy, especially methoxy, ethoxy, propoxy, isopropoxy, n-butyloxy, sec-butyloxy, iso-butyloxy or tert-butyloxy, preferably methoxy.
C1-C8alkoxy and C1-C4alkoxy have the same meanings as given for C1-C12alkoxy up to the corresponding number of C-atoms.
C1-C8alkylthio, for example C1-C6- or C1-C4alkylthio is linear or branched and is, for example methylthio, ethylthio, n-propylthio, i-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio, pentylthio, hexylthio or octylthio, preferably methylthio or butylthio.
Phenyl-C1-C3-alkyl is for example benzyl, phenylethyl, a-methylbenzyl or xcex1,xcex1-dimethylbenzyl, especially benzyl. Substituted phenyl-C1-C3alkyl is substituted one to four times, for example once, twice or three times, especially twice or three times, on the phenyl ring.
Substituted phenyl is substituted one to four times, for example once, twice or three times, especially once or twice. Substituents are, for example in position 2, 3, 4, 5 or 6, especially in position 2, 6 or 3 of the phenyl ring.
Mono- or polysubstituted phenyl is substituted one to four times, for example once, twice or three times, especially once or twice.
Halogen is fluorine, chlorine, bromine and iodine, especially fluorine, chlorine and bromine, preferably bromine and chlorine.
Examples for Ar being a group of formula V are 
wherein L is O,
G is C2- or C3alkylene and E is a direct bond.
AFA type chain transfer group-containing photoinitiator compounds are obtained, for instance, by reacting thiol-containing photoinitiators and AFA type chain transfer agents. AFA type chain transfer agents are disclosed, for example, in WO 88/04304 and U.S. Pat. No. 5,395,903.
More specifically, AFA type of chain transfer group-containing photoinitiators can be prepared by treating thiol-containing photoinitiators with monomers, for example, methyl 2-(bromomethyl)acrylate, 2-(bromomethyl)acrylic acid, ethyl 1,3-dibromopropane-2-carboxylate, 1,3-dibromopropane-2-carboxylic acid, or -(bromomethyl)styrene.
These reactions are carried out in a solvent such as methanol, ethanol, dichloromethane, tetrahydrofuran (THF) or dimethylformamide (DMF) in the presence of a base, for example potassium carbonate, potassium hydrogen carbonate, sodium carbonate, sodium hydroxide, or triethylamine, and generally are carried out at a temperature of xe2x88x9220xc2x0 C. to 80xc2x0 C., preferably 0xc2x0 C. to 40xc2x0 C. These methods are known to the person skilled in the art and described, for example, in Macromolecules 24, 3689-3695 (1991).
Another preparation method is, for example, the condensation of hydroxy group or amine group containing photoinitiators with the corresponding acrylic acid (e.g. 2-(butylmercaptomethyl)acrylic acid, 2-(bromomethyl)acrylic acid etc.) using condensation reagents such as 1,3-dicyclohexylcarbodiimide (hereinafter called xe2x80x9cDCCxe2x80x9d).
These reactions for example are carried out in a solvent such as dichloromethane, THF, DMF, chloroform, or toluene at a temperature of xe2x88x9220xc2x0 C. to 50xc2x0 C., preferably 0xc2x0 C. to 30xc2x0 C. These methods are described, for example, in Can. J. Chem., 66, 1701-1705 (1988).
The preparation of thiol-containing photoinitiators, which are used as starting materials to prepare the compounds of the present invention is known and for example described in U.S. Pat. No. 5,077,402 and GB 2320027. These thiol-containing photoinitiator compounds can, for example, be prepared from halophenyl aliphatic ketones by treatment with an excess of the corresponding dithiol or polythiol. Thiol compounds can for example also be obtained from the corresponding vinyl, hydroxy, halogen or amino precursors by known methods. See, for example xe2x80x9cThe Chemistry of the Thiol Groupxe2x80x9d, ed. S. Patai, John Wiley and Sons, p. 163, New York, 1974. Further, hydroxy groups can be transformed to thiol groups by the reaction with hydrogen sulfide or phosphorous pentasulfides, or via the corresponding halogens. The esterification of alcohols with a mercaptocarboxylic acid, such as mercaptoacetic acid or mercaptopropionic acid provides another convenient access to thiols. Amines can be converted to thiols by alkylation with mercapto halides or by amidation with a mercaptocarboxylic acid, such as mercaptoacetic acid or mercaptopropionic acid. The performance of such reactions and the reaction conditions for such reactions are generally known to the person skilled in the art.
Preference is given to compounds of formula Ia, wherein when n is 1, CT is a group of formula IXa or IXb and when n is 2, CT is a group of formula XI.
Other preferred compounds are such, wherein PI is a group of formula IIa;
Ar2 is 
xe2x80x83which is unsubstituted or substituted 1 to 4 times by halogen, C1-C12alkyl, or xe2x80x94OR7;
R1 and R2 independently of one another are C1-C8alkyl, which is unsubstituted or substituted by OH, or C1-C4alkoxy, or R1 and R2 independently of one another are C3-C6alkenyl, phenyl, chlorophenyl, or phenyl-C1-C3-alkyl, or R1 and R2 independently of one another are a radical of formula VII or VIII;
Ar3 is phenyl;
M1 is xe2x80x94NR3R4;
R3 is hydrogen, C1-C12alkyl; or R3 is C3-C5alkenyl, C5-C12-cycloalkyl or phenyl-C1-C3alkyl;
R4 is C1-C12alkyl; or R3 and R4 together are C3-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94;
R7 is hydrogen, or C1-C12alkyl;
R13, R14, R15 and R16 are hydrogen;
A1 is a direct bond, xe2x80x94X[(CH2)lXxe2x80x2]qxe2x80x94[(C6H4)oXxe2x80x3]rxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
R6 is hydrogen or C1-C12alkyl;
X, Xxe2x80x2 and Xxe2x80x3 independently of each other are a direct bond, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, or xe2x80x94N(R6)xe2x80x94;
l is an integer from 0 to 4;
q is an integer 0 or 1;
CT when n is 1, is a group of formula IXa or IXb
or, when n is 2, CT is a group of formula XI,
Y is xe2x80x94W(R8)s;
Yxe2x80x2 is xe2x80x94W(R8)tR25xe2x80x94;
W is S;
R8 is hydrogen or C1-C12alkyl;
Z is xe2x80x94COOR7, xe2x80x94CONR9R10, or xe2x80x94Ar;
R9 and R10 independently of each other are hydrogen or C1-C12alkyl;
Ar is phenyl;
Zxe2x80x2 is xe2x80x94COOR25xe2x80x94 or xe2x80x94CONR9R25xe2x80x94;
u and t are 0;
s is 1;
R23 and R24 are hydrogen; and
R25 is a direct bond or C1-C4alkylene.
The photoinitiator compounds of formula Ia and Ib according to the invention can be used as chain transfer agents.
The macrophotoinitiators are obtained by thermally polymerizing a monomer and the above defined photoinitiator compound comprising an AFA type chain transfer group. Another object of the invention is a macrophotoinitiator obtained by thermally polymerizing a monomer and a photoinitiator compound of formula Ia or Ib.
Suitable monomers to prepare the macrophotoinitiators according to the invention are of formula XIII 
wherein
X1 is xe2x80x94CN, xe2x80x94OSi(R26)3, xe2x80x94R27, xe2x80x94OR28, xe2x80x94SR28, xe2x80x94NR29R30, 
xe2x80x83or X1 is phenyl or benzyl each of which is unsubstituted or substituted by halogen, C1-C12alkyl, C1-C12alkoxy, C3-C8cycloalkyl, xe2x80x94COOH, xe2x80x94COO(C1-C12alkyl), xe2x80x94O(CO)O(C1-C12alkyl), tetrahydropyranyloxy, tetrahydrofuranyloxy, or tetrahydrofurfuryloxy;
Y1, Y2 and Y3 independently of one another are hydrogen, C1-C4alkyl, halogen, xe2x80x94CN or xe2x80x94COOR7; or Y1 and Y3 together are C3-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94 and which C3-C7alkylene is unsubstituted or substituted by OH, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl);
X2 is xe2x80x94OSi(R26)3, xe2x80x94R27, xe2x80x94OR28, xe2x80x94SR28, xe2x80x94NR29R30;
R26 independently of one another are hydrogen; C1-C20alkyl, C3-C12-alkenyl, C3-C8cycloalkyl, C4-C8cycloalkenyl, each of which is unsubstituted or mono- or polysubstituted by F, Cl, Br, CN, xe2x80x94N(C1-C4alkyl)2, piperidino, morpholino, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C4alkyl)2, xe2x80x94CO(C1-C4alkyl) or by 
or R26 is 2,3-epoxypropyl, xe2x80x94(CH2CH2O)mH or xe2x80x94(CH2CH2O)mR19;
or R26 is phenyl, pyridinyl, biphenylyl or benzoylphenyl each of which is unsubstituted or mono- or polysubstituted by halogen, C1-C12alkyl, C1-C12alkoxy, C3-C8cycloalkyl, xe2x80x94COOH, or xe2x80x94COO(C1-C12alkyl); or R26 is phenyl-C1-C3alkyl, OR7, xe2x80x94NR9R10, or xe2x80x94NHCOR9;
R27 is hydrogen; C1-C20alkyl, C3-C12-alkenyl, C3-C8cycloalkyl, C4-C8 cycloalkenyl each of which is unsubstituted or mono- or polysubstituted by F, Cl, Br, CN, xe2x80x94N(C1-C4alkyl)2, phenyl, phenoxy, piperidino, morpholino, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C4alkyl)2, xe2x80x94CO(C1-C4alkyl) or by 
or R27 is 2,3-epoxypropyl, or xe2x80x94(CH2CH2O)mH;
or R27 is phenyl, pyridinyl, biphenylyl, benzyl or benzoylphenyl each of which is unsubstituted or mono- or polysubstituted by halogen, C1-C12alkyl, C1-C12alkoxy, C3-C8cycloalkyl, xe2x80x94COOH, xe2x80x94COO(C1-C12alkyl), xe2x80x94O(CO)O(C1-C12alkyl), tetrahydropyranyloxy, tetrahydrofuranyloxy, or tetrahydrofurfuryloxy;
or R27 is phenyl-C1-C3alkyl, tetrahydropyranyl, tetrahydrofuranyl, adamantyl, camphoryl; and optionally R27 contains one or more reactive substituents of formula 
R28 is hydrogen; C1-C20alkyl, C3-C12-alkenyl, C3-C8cycloalkyl, C4-C8cycloalkenyl each of which is unsubstituted or mono- or polysubstituted by F, Cl, Br, CN, xe2x80x94N(C1-C4alkyl)2, phenyl, phenoxy, piperidino, morpholino, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C4alkyl)2, xe2x80x94CO(C1-C4alkyl) or by 
or R28 is 2,3-epoxypropyl, or xe2x80x94(CH2CH2O)mH;
or R28 is phenyl, pyridinyl, biphenylyl, benzyl or benzoylphenyl each of which is unsubstituted or mono- or polysubstituted by halogen, C1C12alkyl, C1-C12alkoxy, C3-C8cycloalkyl, xe2x80x94COOH, xe2x80x94COO(C1-C12alkyl), xe2x80x94O(CO)O(C1-C12alkyl), tetrahydropyranyloxy, tetrahydrofuranyloxy, or tetrahydrofurfuryloxy;
or R28 is phenyl-C1-C3alkyl, tetrahydropyranyl, tetrahydrofuranyl, adamantyl, camphoryl; and
optionally R28 contains one or more reactive substituents of formula 
R29 and R30 independently of one another are hydrogen; C1-C12alkyl, or C2-C4alkyl each of which is substituted by OH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl);
or R29 and R30 independently of one another are C3-C5alkenyl, cyclohexyl, phenyl-C1-C3alkyl, adamantyl, camphoryl unsubstituted phenyl or phenyl which is mono- or poly-substituted by C1-C12alkyl or halogen;
or R29 and R30 together are C2-C7alkylene optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
Y4 is hydrogen or CH3;
Z1 is xe2x80x94Oxe2x80x94 or xe2x80x94N(R28)xe2x80x94;
R6 is hydrogen, C1-C12alkyl, OH-substituted C1-C12alkyl, SH-substituted C1-C12alkyl or HSxe2x80x94(CH2)nxe2x80x94COO-substituted C1-C12alkyl; C2-C12alkyl, which is interrupted by xe2x80x94Oxe2x80x94, xe2x80x94NHxe2x80x94 or xe2x80x94Sxe2x80x94; or R6 is C3-C5alkenyl, phenyl-C1-C3-alkyl, xe2x80x94CH2CH2CN, C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, OH-substituted C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, SH-substituted C2-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, C2-C8alkanoyl, OH-substituted C2-C8alkanoyl, SH-substituted C2-C8alkanoyl or benzoyl; and
n is 1 or 2.
Accordingly, a subject of the invention is a macrophotoinitiator, wherein the monomer is of formula (XIII).
A preferred macrophotoinitiator is of formula XIII, wherein
X1 is xe2x80x94CN, or 
xe2x80x83or X1 is phenyl or benzyl each of which is unsubstituted or substituted by halogen, C1-C12alkyl, C1-C12alkoxy, C3-C8cycloalkyl, xe2x80x94COOH, xe2x80x94COO(C1-C12alkyl), xe2x80x94O(CO)O(C1-C12alkyl), tetrahydropyranyloxy, tetrahydrofuranyloxy, or tetrahydrofurfuryloxy;
Y1 and Y2 are hydrogen;
Y3 is hydrogen or C1-C4 alkyl;
X2 is xe2x80x94OR28 or xe2x80x94NR29R30.
Suitable monomers are hydrophilic, amphiphilic or hydrophobic.
Examples of hydrophilic monomers are (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-isopropenyl(meth)acrylamide, N-vinylformamide, (meth)acrylic acid, crotonic acid, itaconic acid, cinnamic acid, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, maleic acid, maleic acid anhydride, n-(1,1-dimethyl 3-oxobutyl)(meth)acrylate, 4-hydroxystyrene, 4-hydroxymethyl styrene, p-1-(2-hydroxybutyl)styrene, p-1-(2-hydroxypropyl)styrene, p-2-(2-hydroxypropyl)styrene and styrene sulfonic acid.
Examples of amphiphilic monomers or oligomers are (meth)acrylonitrile, N-(meth)acrylmorpholine, N-vinylpyrrolidone, N-vinylacetamide, N-vinyl-N-methylacetamide, vinyl methyl ether. Polyethylene glycol mono-(meth)acrylate, methoxy poly(ethylene glycol)mono-(meth)acrylate, poly(propylene glycol)mono-(meth)acrylate. N-vinylcaprolactam, N-vinylcarbazole, 4-vinylbenzyl tetrahydrofurfuryl ether and glycidyl(meth)acrylate.
Examples of hydrophobic monomers are methyl(meth)acrylate, ethyl(meth)acrylate, n-butyl(meth)acrylate, tert-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isobornyl(meth)acrylate, lauryl(meth)acrylate, stearyl(meth)acrylate, 1-naphtyl(meth)acrylate, 2-naphtyl(meth)acrylate, adamantyl(meth)acrylate, styrene, 2,4,6-trimethystyrene, 2,5-dichlorostyrene, xcex1-methoxystyrene, xcex1-methylstyrene, 3-methylstyrene, 4-methylstyrene, 3-nitrostyrene, 4-chloromethylstyrene, 4-aminostyrene, 4-tert-butylstyrene, 4-tert-butoxycarbonyloxystyrene, 3-bromostyrene, 4-bromostyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 4-cyanostyrene, 4-cyclohexylstyrene, dimethylaminomethyl-styrene, pentachlorostyrene, 4-iodostyrene, xcex2-methoxystyrene, 2-methoxystyrene, 4-methoxystyrene, 1- vinylnaphtalene, 2-vinylnaphtalene, vinyl acetate, vinyl propionate, isobutyl vinyl ether, vinyl chloride, 4-vinylbenzyl chloride, 2-fluoroethyl(meth)acrylate, perfluorocyclohexyl(meth)acrylate, perfluorooctyl(meth)acrylate, 2,2,3,3-tetrafluoropropyl(meth)acrylate, 2,2,2-trifluoroethyl(meth)acrylate and 3-(trifluoromethyl)benzyl(meth)acrylate.
The monomers can be used alone or in any desired mixtures.
Preferred monomers are selected from the group consisting of acrylates, methacrylates and styrene derivatives.
The macrophotoinitiators according to the present invention are prepared, by thermally polymerizing a monomer with a photoinitiator having a chain tranfer group as defined above. The person skilled in the art generally knows how to conduct a thermal polymerization.
Generally, thermal initiators can be employed, for instance azobisisobutyronitrile (AIBN), N-acetyl Nxe2x80x2-xcex1-cyanoethyl diimide, 2-cyano-2-propyl-azo-formamide, N-acetyl Nxe2x80x2-xcex1-cyanocyclopentyl diimide, 3,6-dicyano-3,6-dimethyl-1,2-diazocyclo-1-pentane, N-acetyl Nxe2x80x2-xcex1-cyanocycloheptyl diimide, phenyl-azo-triphenylmethane, 4-nitrophenyl-azo-triphenylmethane, 4-methoxyphenyl-azo-2-(methylpropanedinitrile), benzoyl peroxide, methyl ethyl ketone peroxide, t-butyl peroxybenzoate or t-butylperoxy-2-ethyl hexanoate. These compounds usually are added in a concentration from 0.005 mol % to 5 mol %, based on the monomer, preferably in a concentration from 0.05 mol % to 1 mol %.
The photoinitiator having a chain transferring moiety can be combined in any ratio with the monomers to control the molecular weight of the obtained polymer. The molar ratio of photoinitiator:monomer is for example in the range from 1:100,000 to 1:1; preferably from 1:50,000 to 1:1.
The polymerization usually is carried out in bulk or in any solution at any concentration. Examples of suitable solvents are hydrocarbons such as benzene, toluene, xylene, cyclohexane; esters such as ethyl acetate, butyl acetate, amyl acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol, ethanol, isobutyl alcohol 1,2,6-hexanetriol glycerin; amides such as N,N-dimethylformamide, N-methylformamide, N,N-diethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide; pyrrolidones such as 1-methyl-2-pyrrolidone, pyrrolidone xcex5-caprolactam; glycols such as ethylene glycol, propylene glycol, butylene glycol, tri(methylene glycol), tri(ethylene glycol), hexylene glycol, di(ethylene glycol), diethylene glycol, di(propylene glycol), poly(ethylene glycol); glycol ethers such as 2-methoxyethanol, 2-ethoxyethanol, 2-(2-methoxy)ethoxy ethanol, 2-propoxyethanol, 2-butoxyethanol, di(ethylene glycol)monomethyl ether, di(ethylene glycol)monoethyl ether, di(ethylene glycol)monobutyl ether, tri(ethylene glycol)monoethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, di(propylene glycol)monomethyl ether, di(propylene glycol)monoethyl ether, tri(propylene glycol)monomethyl ether, 3-methoxyl-3-methyl-1-butanol; halogenated hydrocarbon, such as chloroform or methylene chloride. The solvent may also be in the form of a mixture of two or more of the above-mentioned solvents.
The polymerization generally is carried out in inert atmosphere in order to avoid inactivation of the generated radicals. Examples of suitable inert gases are nitrogen, helium, neon, argon and xenon.
The polymerization usually is conducted at an appropriate temperature at which the monomers can be polymerized. The temperature strongly depends on the choice of the monomer, initiator and solvent. The temperature generally is in the range from 40xc2x0 C. to 180xc2x0 C., preferably from 60xc2x0 C. to 130xc2x0 C.
The number and weight average molecular weights of the obtained macrophotoinitiator expediently is determined by a common method such as for example (gel permeation chromatography) GPC measurement, calibrated by the standard polystyrene or/and poly(methyl methacrylate). The number and weight average molecular weights of the obtained macrophotoinitiator are in the range from 300 to 10,000,000, preferably from 500 to 1,000,000.
Accordingly, a process for the preparation of a macrophotoinitiator, characterized in that a photoinitiator with a chain transfer group as described above is thermally polymerized with a monomer is another subject of the invention.
The invention also pertains to a macrophotoinintiator, which is obtained by reacting a photoinitiator of formula Ia or Ib, as defined above with a monomer of formula XII.
Preferably the macrophotoinintiator is of formula XIV 
wherein
n is 1 or 2;
PI is a photoinitiator moiety
CT1 is xe2x80x94Yxe2x80x2xe2x80x94, R25xe2x80x94, 
u is 0 or 1;
J is a polymeric group;
A1 is a direct bond, xe2x80x94X[(CH2)lXxe2x80x2]qxe2x80x94[(C6H4)oXxe2x80x3]rxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
X, Xxe2x80x2 and Xxe2x80x3 independently of each other are a direct bond, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94N(R6)xe2x80x94, xe2x80x94O(CO)xe2x80x94, xe2x80x94COOxe2x80x94 xe2x80x94NHCOxe2x80x94, xe2x80x94CONHxe2x80x94 or xe2x80x94COxe2x80x94;
l is an integer from 0 to 10;
q is an integer from 0 to 5;
o and r independently of one another are an integer 0, 1 or 2;
Zxe2x80x2 is xe2x80x94COOR25xe2x80x94, xe2x80x94CONR9R25xe2x80x94, or xe2x80x94Ar2xe2x80x94;
Yxe2x80x2 is xe2x80x94W(R8)txe2x80x94R25xe2x80x94;
t is an integer 0, 1 or 2;
W is S, Si, Se, P, Br, Cl, Sn, xe2x80x94Oxe2x80x94Oxe2x80x94, S(xe2x95x90O), S(xe2x95x90O)2, or P(xe2x95x90O);
Ar2 is 
xe2x80x83each of which is unsubstituted or substituted 1 to 5 times by halogen, C1-C12alkyl, C3-C12alkenyl, C5-C6cycloalkyl, phenyl-C1-C3alkyl, xe2x80x94COOH, xe2x80x94COO(C1-C4alkyl), xe2x80x94OR7, xe2x80x94SR8, xe2x80x94SOR8, xe2x80x94SR2R8, xe2x80x94CN, xe2x80x94SO2NH2, xe2x80x94SO2NH(C1-C4alkyl), xe2x80x94SO2xe2x80x94N(C1-C4alkyl)2, xe2x80x94NR9R10, xe2x80x94NHCOR9, or by a group of formula IV 
or Ar2 is a group of formula Va or VIa 
G is unbranched or branched C1-C7alkylene;
L and E independently of one another are a direct bond, xe2x80x94Oxe2x80x94,xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94, provided that L and E are not both a direct bond simultaneously;
R1 and R2 independently of one another are R7Oxe2x80x94, C1-C8alkyl, which is unsubstituted or substituted by OH, C1-C4alkoxy, SR8, CN, (C1-C8alkyl)O(CO)xe2x80x94, (C1-C4alkyl)-(OC)Oxe2x80x94 or xe2x80x94N(R3)(R4), or R1 and R2 independently of one another are C3-C6alkenyl, phenyl, chlorophenyl, R7xe2x80x94O-phenyl, R8xe2x80x94S-phenyl or phenyl-C1-C3-alkyl, or R1 and R2 together are unbranched or branched C2-C9alkylene, C3-C9oxaalkylene or C3-C9azaalkylene, or R1 and R2 independently of one another are a radical of formula VII or VIII 
Ar3 is phenyl, naphthyl, furyl, thienyl or pyridiyl, each of which is unsubstituted or substituted by halogen, SH, OH, C1-C12alkyl, OH-substituted C1-C4alkyl, halogen-substituted C1-C4alkyl, SH-substituted C1-C4alkyl, N(R17)2-substituted C1-C4alkyl, C1-C12alkoxy-substituted C1-C4alkyl, (C1-C18alkyl)O(OC)-substituted C1-C4alkyl, CH3O(CH2CH2O)mCO-substituted C1-C4alkyl, (C1-C4alkyl)(OC)O-substituted C1-C4alkyl, C1-C12alkoxy, (C1-C18alkyl)(OC)O-substituted C1-C4alkoxy, CH3O(CH2CH2O)mCO-substituted C1-C4alkoxy, xe2x80x94(OCH2CH2)mOH, xe2x80x94(OCH2CH2)mOCH3, C1-C8alkylthio, phenoxy, xe2x80x94COO(C1-C18alkyl), xe2x80x94CO(OCH2CH2)mOCH3, phenyl or benzoyl;
m is 1 to 20;
R3 is hydrogen, C1-C12alkyl, C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R3 is C3-C5alkenyl , C5-C12-cycloalkyl or phenyl-C1-C3alkyl;
R4 is C1-C12alkyl; C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R4 is C3-C5alkenyl, C5-C12-cycloalkyl, phenyl-C1-C3alkyl; phenyl which is unsubstituted or substituted by halogen, C1-C12alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl);
or R4 together with R2 is C1-C7alkylene, phenyl-C1-C4alkylene, o-xylylene, 2-butenylene, C2-C3oxaalkylene or C2-C3azaalkylene; or R3 and R4 together are C3-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94 and which C3-C7alkylene is unsubstituted or substituted by OH, SH, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl);
R6 is hydrogen, C1-C12alkyl, OH-substituted C1-C12alkyl, SH-substituted C1-C12alkyl or HSxe2x80x94(CH2)nxe2x80x94COO-substituted C1-C12alkyl; C2-C12alkyl, which is interrupted by xe2x80x94Oxe2x80x94, xe2x80x94NHxe2x80x94 or xe2x80x94Sxe2x80x94; or R6 is C3-C5alkenyl, phenyl-C1-C3-alkyl, xe2x80x94CH2CH2CN, C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, OH-substituted C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, SH-substituted C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, C2-C8alkanoyl, OH-substituted C2-C8alkanoyl, SH-substituted C2-C8alkanoyl or benzoyl;
R7 is hydrogen, C1-C12alkyl, C3-C12-alkenyl, cyclohexyl, hydroxycyclohexyl; C1-C4alkyl, which is mono- or polysubstituted by Cl, Br, CN, SH, xe2x80x94N(C1-C4alkyl)2, piperidinyl, morpholinyl, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C4alkyl)2, 
xe2x80x83xe2x80x94CO(C1-C4alkyl) or by 
xe2x80x83or R7 is 2,3-epoxypropyl, xe2x80x94(CH2CH2O)nH; phenyl which is unsubstituted or substituted by halogen, C1-C4alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl); or R7 is phenyl-C1-C3-alkyl, tetrahydropyranyl, tetrahydrofuranyl, xe2x80x94COOR19, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C8alkyl)2, xe2x80x94Si(R20)(R21)2, or xe2x80x94SO2R22;
R8 is hydrogen, C1-C12alkyl, C3-C12alkenyl, cyclohexyl, hydroxycyclohexyl; C1-C4alkyl, which is mono- or polysubstituted by Cl, Br, CN, SH, xe2x80x94N(C1-C4alkyl)2, piperidinyl, morpholinyl, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8-alkyl), xe2x80x94CON(C1-C4alkyl)2, 
xe2x80x83xe2x80x94CO(C1-C4alkyl) or 
xe2x80x83or R8 is 2,3-epoxypropyl, phenyl-C1-C3alkyl, phenyl-C1-C3hydroxyalkyl; phenyl which is unsubstituted or mono- or poly-substituted by halogen, SH, C1-C4alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl); or
R8 is 2-benzothiazyl, 2-benzimidazolyl, xe2x80x94CH2CH2xe2x80x94Oxe2x80x94CH2CH2xe2x80x94SH or xe2x80x94CH2CH2xe2x80x94Sxe2x80x94CH2CH2xe2x80x94SH;
R9 and R10 independently of one another are hydrogen, C1-C12alkyl; C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R9 and R10 independently of one another are C3-C5alkenyl, cyclohexyl, phenyl-C1-C3alkyl; phenyl which is unsubstituted or mono- or poly-substituted by C1-C12alkyl or halogen; or R9 and R10 together are C2-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
R11 and R12 independently of one another are a direct bond, xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94; provided that R11 and R12 are not a direct bond simultaneously;
R13 is hydrogen, C1-C8alkyl or phenyl;
R14, R15 and R16 independently of one another are hydrogen or C1-C4alkyl;
R17 is hydrogen, C1-C8alkyl or phenyl;
R19 is C1-C4alkyl, C2-C4alkenyl or phenyl;
R20 and R21 independently of one another are C1-C4alkyl or phenyl;
R22 is C1-C18alkyl; or phenyl which is unsubstituted or substituted by C1-C14alkyl;
R23 and R24 independently of one another are hydrogen, or C1-C8alkyl; or R23 and R24 together are C5-C7cyloalkyl; and
R25 is a direct bond, C1-C4alkylene or phenylene.
J as a polymeric group is to be understood as a radical resulting from a polymer or of a copolymer. Examples for polymer groups J are radicals of poly(methacrylate), poly(acrylate), poly(methacrylic acid), poly(acrylic acid), polystyrene, derivatives of polystyrene, poly(diene), polyacrylonitrile, poly(vinyl alcohol), poly(vinyl ester). Examples for copolymer groups J are radicals of poly(methacrylates), poly(acrylates), poly(methacrylates-co-styrene), poly(acrylates-co-styrene). Preferred are poly(methacrylate), poly(acrylate), poly(methacrylic acid), poly(acrylic acid), and polystyrene.
If CT1 is a group 
with u=0 a CT1 is 
if u=1 a group 
is meant.
Preferred are macrophotoinitiators, wherein PI is a group of formula IIa.
In particular interesting are macrophotoinitiators of formula XIV, wherein
PI is a group of formula IIa 
CT1 is xe2x80x94Yxe2x80x2xe2x80x94, xe2x80x94R25xe2x80x94 or 
u and t are 0;
l is an integer from 0 to 4;
q is an integer 0 or 1;
o and r independently of one another are an integer 0, 1 or 2;
Zxe2x80x2 is xe2x80x94COOR25xe2x80x94 or xe2x80x94CONR9R25xe2x80x94;
Yxe2x80x2 is xe2x80x94W(8)txe2x80x94R25xe2x80x94;
W is S;
Ar2 is 
xe2x80x83which is unsubstituted or substituted 1 to 4 times by halogen, C1-C12alkyl or xe2x80x94OR7;
R1 and R2 independently of one another are C1-C8alkyl which is unsubstituted or substituted by OH, or C1-C4alkoxy; or R1 and R2 independently of one another are C3-C6alkenyl, phenyl, chlorophenyl, or phenyl-C1-C3-alkyl; or R1 and R2 independently of one another are a radical of formula VII or VIII;
Ar3 is phenyl;
M1 is xe2x80x94NR3R4;
R3 is hydrogen, C1-C12alkyl, C3-C5alkenyl, C5-C12cycloalkyl or phenyl-C1-C3alkyl;
R4 is C1-C12alkyl; or R3 and R4 together are C3-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94;
R6, R7, R8 and R9 independently of each other are hydrogen or C1-C12alkyl;
R13, R14, R15, R16, R23 and R24 are hydrogen; and
R25 is a direct bond, or C1-C4alkylene.
In accordance with the invention, the macrophotoinitiators can be used as photoinitiators for the photopolymerization of ethylenically unsaturated compounds or of mixtures which comprise such compounds.
The invention therefore also relates to photopolymerizable compositions comprising
(A) at least one ethylenically unsaturated photopolymerizable compound and
(B) at least one macrophotoinitiator as described above.
The composition may comprise additionally to the component (B) at least one further photoinitiator (C), and/or further coinitiators (D) and/or other additives (E).
The photosensitivity of the novel compositions as described above can extend in general from about 200 nm to 600 nm (UV region).
Ethylenically unsaturated photopolymerizable compounds, component (A), may include one or more olefinic double bonds. They may be of low (monomeric) or high (oligomeric) molecular mass. Examples of monomers containing a double bond are alkyl or hydroxyalkyl acrylates or methacrylates, for example methyl, ethyl, butyl, 2-ethylhexyl or 2-hydroxyethyl acrylate, isobornyl acrylate, methyl methacrylate or ethyl methacrylate. Silicone acrylates are also advantageous. Other examples are acrylonitrile, acrylamide, methacrylamide, N-substituted (meth)acrylamides, vinyl esters such as vinyl acetate, vinyl ethers such as isobutyl vinyl ether, styrene, alkyl- and halostyrenes, N-vinylpyrrolidone, vinyl chloride or vinylidene chloride.
Examples of monomers containing two or more double bonds are the diacrylates of ethylene glycol, propylene glycol, neopentyl glycol, hexamethylene glycol or of bisphenol A, and 4,4xe2x80x2-bis(2-acryl-oyloxyethoxy)diphenylpropane, trimethylolpropane triacrylate, pentaerythritol triacrylate or tetraacrylate, vinyl acrylate, divinylbenzene, divinyl succinate, diallyl phthalate, triallyl phosphate, triallyl isocyanurate or tris(2-acryloylethyl)isocyanurate.
Examples of polyunsaturated compounds of relatively high molecular mass (oligomers) are acrylisized epoxy resins, acrylisized polyesters, polyesters containing vinyl ether or epoxy groups, and also polyurethanes and polyethers. Further examples of unsaturated oligomers are unsaturated polyester resins, which are usually prepared from maleic acid, phthalic acid and one or more diols and have molecular weights of from about 500 to 3,000. In addition it is also possible to employ vinyl ether monomers and oligomers, and also maleate-terminated oligomers with polyester, polyurethane, polyether, polyvinyl ether and epoxy main chains. Of particular suitability are combinations of oligomers which carry vinyl ether groups and of polymers as described in WO 90/01512. However, copolymers of vinyl ether and maleic acid-functionalized monomers are also suitable. Unsaturated oligomers of this kind can also be referred to as prepolymers.
Particularly suitable examples are esters of ethylenically unsaturated carboxylic acids and polyols or polyepoxides, and polymers having ethylenically unsaturated groups in the chain or in side groups, for example unsaturated polyesters, polyamides and polyurethanes and copolymers thereof, alkyd resins, polybutadiene and butadiene copolymers, polyisoprene and isoprene copolymers, polymers and copolymers containing (meth)acrylic groups in side chains, and also mixtures of one or more such polymers.
Examples of unsaturated carboxylic acids are acrylic acid, methacrylic acid, crotonic acid, itaconic acid, cinnamic acid, and unsaturated fatty acids such as linolenic acid or oleic acid. Acrylic and methacrylic acid are preferred.
Suitable polyols are aromatic and, in particular, aliphatic and cycloaliphatic polyols. Examples of aromatic polyols are hydroquinone, 4,4xe2x80x2-dihydroxydiphenyl and 2,2-di(4-hydroxyphenyl)propane. Examples of polyepoxides are those based on the above mentioned polyols, especially the aromatic polyols, and epichlorohydrin. Other suitable polyols are polymers or copolymers containing hydroxyl groups in the polymer chain or in side groups, examples being polyvinyl alcohol and copolymers thereof, polyhydroxyalkyl methacrylates or copolymers thereof or novolak resins. Further polybis which are suitable are oligoesters having hydroxyl end groups.
Examples of aliphatic and cycloaliphatic polyols are alkylenediols having preferably 2 to 12 carbon atoms, such as ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol, hexanediol, octanediol, dodecanediol, diethylene glycol, triethylene glcyol, polyethylene glycols having molecular weights of preferably from 200 to 1500, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,4-dihydroxymethylcyclohexane, glycerol, tris(xcex2-hydroxyethyl)amine, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol and sorbitol.
The polyols may be partially or completely esterified with one carboxylic acid or with different unsaturated carboxylic acids, and in partial esters the free hydroxyl groups may be modified, for example etherified or esterified with other carboxylic acids.
Examples of esters are: trimethylolpropane triacrylate, trimethylolethane triacrylate, trimethylolpropane trimeth-acrylate, trimethylolethane trimethacrylate, tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritol octaacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol tetramethacrylate, tripentaerythritol octamethacrylate, pentaerythritol diitaconate, dipentaerythritol tris-itaconate, dipentaerythritol pentaitaconate, dipentaerythritol hexaitaconate, ethylene glycol diacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diitaconate, sorbitol triacrylate, sorbitol tetraacrylate, pentaerythritol-modified triacrylate, sorbitol tetra methacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, oligoester acrylates and methacrylates, glycerol diacrylate and triacrylate, 1,4-cyclohexane diacrylate, bisacrylates and bismethacrylates of polyethylene glycol with a molecular weight of from 200 to 1500, or mixtures thereof.
Also suitable are the amides of identical or different, unsaturated carboxylic acids with aromatic, cycloaliphatic and aliphatic polyamines having preferably 2 to 6, especially 2 to 4, amino groups. Examples of such polyamines are ethylenediamine, 1,2- or 1,3-propylenediamine, 1,2-, 1,3- or 1,4-butylenediamine, 1,5-pentylenediamine, 1,6-hexylenediamine, octylenediamine, dodecylenediamine, 1,4-diaminocyclohexane, isophoronediamine, phenylenediamine, bisphenylenediamine, di-xcex2-aminoethyl ether, diethylenetriamine, triethylenetetramine, di(xcex2-aminoethoxy)- or di(xcex2-aminopropoxy)ethane. Other suitable polyamines are polymers and copolymers, preferably with additional amino groups in the side chain, and oligo-amides having amino end groups. Examples of such unsaturated amides are methylenebisacrylamide, 1,6-hexamethylenebisacrylamide, diethylenetriaminetrismethacrylamide, bis(methacrylamidopropoxy)ethane, 1-methacrylamidoethyl methacrylate and N[(xcex2-hydroxyethoxy)ethyl]acrylamide.
Suitable unsaturated polyesters and polyamides are derived, for example, from maleic acid and from diols or diamines. Some of the maleic acid can be replaced by other dicarboxylic acids. They can be used together with ethylenically unsaturated comonomers, for example styrene. The polyesters and polyamides may also be derived from dicarboxylic acids and from ethylenically unsaturated diols or diamines, especially from those with relatively long chains of, for example 6 to 20 carbon atoms. Examples of polyurethanes are those composed of saturated or unsaturated diisocyanates and of unsaturated or, respectively, saturated diols.
Polybutadiene and polyisoprene and copolymers thereof are known. Examples of suitable comonomers are olefins, such as ethylene, propene, butene and hexene, (meth)acrylates, acrylonitrile, styrene or vinyl chloride. Polymers with (meth)acrylate groups in the side chain are likewise known. They may, for example, be reaction products of epoxy resins based on novolaks with (meth)acrylic acid, or may be homo- or copolymers of vinyl alcohol or hydroxyalkyl derivatives thereof which are esterified with (meth)acrylic acid, or may be homo- and copolymers of (meth)acrylates which are esterified with hydroxyalkyl(meth)acrylates.
The photopolymerizable compounds can be used alone or in any desired mixtures. Preferably used are mixtures of polyol(meth)acrylates.
Binders as well can be added to the novel compositions, and this is particularly expedient when the photopolymerizable-compounds are liquid or viscous substances. The quantity of binder may, for example, be 5-95%, preferably 10-90% and especially 40-90%, by weight relative to the overall solids content. The choice of binder is made depending on the field of application and on properties required for this field, such as the capacity for development in aqueous and organic solvent systems, adhesion to substrates and sensitivity to oxygen.
Examples of suitable binders are polymers having a molecular weight of about 5,000 to 2,000,000, preferably 10,000 to 1,000,000. Examples are: homo- and copolymers of acrylates and methacrylates, for example copolymers of methyl methacrylate/ethyl acrylate/methacrylic acid, poly(alkyl methacrylates), poly(alkyl acrylates); cellulose esters and cellulose ethers, such as cellulose acetate, cellulose acetobutyrate, methylcellulose, ethylcellulose; polyvinylbutyral, polyvinylformal, cyclized rubber, polyethers such as polyethylene oxide, polypropylene oxide and polytetrahydrofuran; polystyrene, polycarbonate, polyurethane, chlorinated polyolefins, polyvinyl chloride, vinyl chloride/vinylidene copolymers, copolymers of vinylidene chloride with acrylonitrile, methyl methacrylate and vinyl acetate, polyvinyl acetate, copoly(ethylene/vinyl acetate), polymers such as polycaprolactam and poly(hexamethylenadipamide), and polyesters such as poly(ethylene glycol terephtalate) and poly(hexamethylene glycol succinate) and polyimides.
The unsaturated compounds can also be used as a mixture with non-photopolymerizable, film-forming components. These may, for example, be physically drying polymers or solutions thereof in organic solvents, for instance nitrocellulose or cellulose acetobutyrate. They may also, however, be chemically and/or thermally curable (heat-curable) resins, examples being polyisocyanates, polyepoxides and melamine resins, as well as polyimide precursors.
The use of heat-curable resins at the same time is important for use in systems known as hybrid systems, which in a first stage are photopolymerized and in a second stage are cross-linked by means of thermal aftertreatment.
The macrophotoinitiators according to the invention are further suitable as initiators for curing of oxidative drying systems, such as are for example described in xe2x80x9cLehrbuch der Lacke und Beschichtungenxe2x80x9d, [textbook on varnishes and coatings] Vol. III, 296-328, Verlag W. A. Colomb in Heenemann GmbH, Berlin-Oberschwandorf (1976).
In addition to the photoinitiator the photopolymerizable mixtures may include various additives (E). Examples of these are thermal inhibitors, which are intended to prevent premature polymerization, examples being hydroquinone, hydroquinine derivatives, p-methoxyphenol, xcex2-naphthol or sterically hindered phenols, such as 2,6-di-tert-butyl-p-cresol. In order to increase the stability on storage in the dark it is possible, for example, to use copper compounds, such as copper naphthenate, stearate or octoate, phosphorus compounds, for example triphenylphosphine, tributylphosphine, triethyl phosphite, triphenyl phosphite or tribenzyl phosphite, quaternary ammonium compounds, for example tetramethylammonium chloride or trimethylbenzylammonium chloride, or hydroxylamine derivatives, for example N-diethylhydroxylamine. To exclude atmospheric oxygen during the polymerization it is possible to add paraffin or similar wax-like substances which, being of inadequate solubility in the polymer, migrate to the surface in the beginning of polymerization and form a transparent surface layer which prevents the ingress of air. It is also possible to apply an oxygen-impermeable layer. Light stabilizers which can be added in a small quantity are UV absorbers, for example those of the hydroxyphenylbenzotriazole, hydroxyphenyl-benzophenone, oxalamide or hydroxyphenyl-s-triazine type. These compounds can be used individually or in mixtures, with or without sterically hindered amines (HALS).
Examples of such UV absorbers and light stabilizers are
1. 2-(2xe2x80x2-hydroxyphenyl)benzotriazoles for example 2-(2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl)benzotriazole, 2-(3xe2x80x2,5xe2x80x2-di-tert-butyl-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(5xe2x80x2-tert-butyl-2xe2x80x2-hydro-xyphenyl)-benzotriazole, 2-(2xe2x80x2-hydroxy-5xe2x80x2-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3xe2x80x2,5xe2x80x2-di-tert-butyl-2xe2x80x2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl)-5-chlorobenzotriazole, 2-(3xe2x80x2-sec-butyl-5xe2x80x2-tert-butyl-2xe2x80x2-hydroxyphenyl)benzotrizole, 2-(2xe2x80x2-hydroxy-4xe2x80x2-octoxyphenyl)benzotriazole, 2-(3xe2x80x2,5xe2x80x2-di-tert-amyl-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(3xe2x80x2,5xe2x80x2-bis-(xcex1,xcex1-dimethylbenzyl)-2xe2x80x2-hydroxyphenyl)-benzotriazole, mixture of 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3xe2x80x2-tert-butyl-5xe2x80x2-[2-(2-ethylhexyl-oxy)carbonylethyl]-2xe2x80x2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-methoxycarbonylethyl)phenyl)-benzotriazole, 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3xe2x80x2-tert-butyl-5xe2x80x2-[2-(2-ethylhexyloxy)carbonylethyl]-2xe2x80x2-hydroxyphenyl)benzotriazole, 2-(3xe2x80x2-dodecyl-2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl)benzotriazole, and 2-(3xe2x80x2-tert-butyl-2xe2x80x2-hydroxy-5xe2x80x2-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2xe2x80x2-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-yl-phenol]; transesterification product of 2-[3xe2x80x2-tert-butyl-5xe2x80x2-(2-methoxycarbonylethyl)-2xe2x80x2-hydroxy-phenyl]-benzotriazole with polyethylene glycol 300; [Rxe2x80x94CH2CH2xe2x80x94COO(CH2)3]2xe2x80x94 where R=3xe2x80x2-tert-butyl-4xe2x80x2-hydroxy-5xe2x80x2-2H-benzotriazol-2-yl-phenyl.
2. 2-Hydroxybenzophenones, for example the 4-hydroxy-, 4-methoxy-, 4-octoxy-, 4-decyloxy-4-dodecyloxy-, 4-benzyloxy-, 4,2xe2x80x2,4xe2x80x2-trihydroxy- and 2xe2x80x2-hydroxy-4,4xe2x80x2-dimethoxy derivative.
3. Esters of substituted or unsubstituted benzoicacids, for example 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis(4-tert-butybenzoyl)resorcinol, benzoylresorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, and 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.
4. Acrylates, for example isooctyl or ethyl xcex1-cyano-xcex2,xcex2-diphenyl acrylate, methyl xcex1-carbo-methoxycinnamate, butyl or methyl xcex1-cyano-xcex2-methyl-p-methoxycinnamate, methyl xcex1-carboxymethoxy-p-methoxycinnamate and N-(xcex2-carbomethoxy-xcex2-cyanovinyl)-2-methylindoline.
5. Sterically hindered amines, for example bis-(2,2,6,6-tetramethylpiperidyl)sebacate, bis-(2,2,6,6-tetramethylpiperidyl)succinate, bis-(1,2,2,6,6-pentamethylpiperidyl)sebacate, bis-(1,2,2,6,6-pentamethylpiperidyl)n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, condensation product of N,Nxe2x80x2-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexa-methylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine, tris-(2,2,6,6-tetramethyl-4-piperidyl)nitrilo-triacetate, tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane tetraoate, 1,1xe2x80x2-(1,2-ethan-diyl)bis(3,3,5,5-tetramethyl-piperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis-(1,2,2,6,6-pentamethylpiperidyl) 2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl- 1,3,8-triazaspiro-[4.5]-decane-2,4-dione, bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, condensation product of N,Nxe2x80x2-bis-(2,2,6,6-tetra-methyl-4-piperidyl)hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine condensation product of 2-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropyl-amino)ethane, condensation product of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione and 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)-pyrrolidine-2,5-dione.
6. Oxalamides, for example 4,4xe2x80x2-dioctyloxyoxanilide, 2,2xe2x80x2-diethoxyoxanilide, 2,2xe2x80x2-dioctyloxy-5,5xe2x80x2-di-tert-butyloxanilide, 2,2xe2x80x2-didodecyloxy-5,5xe2x80x2di-tert-butyloxanilide, 2-ethoxy-2xe2x80x2-ethyl-oxanilide, N,Nxe2x80x2-bis-(3-dimethylaminopropyl)oxalamide, 2-ethoxy-5-tert-butyl-2xe2x80x2-ethyloxanilide and its mixture with 2-ethoxy-2xe2x80x2-ethyl-5,4xe2x80x2-di-tert-butyloxanilide, mixtures of o- and p-methoxy- and of o- and p-ethoxy-disubstituted oxanalides.
7. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxy-phenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy4-(2-hydroxy-3-butyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-dodecyl/tridecyl-oxy-(2-hydroxypropyl)oxy-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.
8. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythrityl diphosphite, tris-(2,4-di-tert-butylphenyl)phosphite, diisodecyl pentaerythrityl diphosphite, bis-(2,4-di-tert-butylphenyl)pentaerythrityl diphosphite, bis-(2,6-di-tert-butyl4-methylphenyl)pentaerythrityl diphosphite, bis-isodecyloxy pentaerythrityl diphosphite, bis-(2,4-di-tert-butyl-6-methylphenyl)pentaerythrityl diphosphite, bis-(2,4,6-tri-tert-butylphenyl)pentaerythrityl diphosphite, tristearyl sorbityl triphosphite, tetrakis-(2,4-di-tert-butylphenyl)-4,4xe2x80x2-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphocine, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphocine, bis-(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite and bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite.
Further additives known in the art may be added, as for example flow improvers and adhesion promoters.
To accelerate the photopolymerization it is possible to add amines, for example triethanolamine, N-methyldiethanolamine, p-dimethylaminobenzoate or Michler""s ketone. The action of the amines can be intensified by the addition of aromatic ketones of the benzophenone type. Examples of amines which can be used as oxygen scavengers are substituted N,N-dialkylanilines, as are described in EP 339841. Other accelerators, coinitiators and autoxidizers are thiols, thioethers, disulfides, phosphonium salts, phosphine oxides or phosphines, as described, for example, in EP 438123, in GB 2180358 and in JP Kokai Hei 6-68309.
It is further possible to add chain transfer agents which are customary in the art to the compositions according to the invention. Examples are mercaptanes, amines and benzothiazol.
Photopolymerization can also be accelerated by adding further photosentisizers or coinitiators (D) which shift or broaden the spectral sensitivity. These are, in particular, aromatic carbonyl compounds, for example benzophenone, thioxanthone, anthraquinone and 3-acylcoumarin derivatives, and also 3-(aroylmethylene)thiazolines, camphor quinone, but also eosine, rhodamine and erythrosine dyes.
The curing process can be assisted by, in particular, compositions which are pigmented (for example with titanium dioxide), and also by adding a component which under thermal conditions forms free radicals, for example an azo compound such as 2,2xe2x80x2-azobis(4-methoxy-2,4-dimethylvaleronitrile), a triazene, diazo sulfide, pentazadiene or a peroxy compound, for instance a hydroperoxide or peroxycarbonate, for example t-butyl hydroperoxide, as described for example in EP 245639.
The compositions according to the invention may comprise as further additive (D) a photoreducable dye, e.g., xanthene-, benzoxanthene-, benzothioxanthene, thiazine-, pyronine-, porphyrine- or acridine dyes, and/or trihalogenmethyl compounds which can be cleaved by irradiation. Similar compositions are for example described in EP 445624.
Further customary additives, depending on the intended use, are optical brighteners, fillers, pigments, dyes, wetting agents or levelling assistants.
In order to cure thick and pigmented coatings it is appropriate to add glass microspheres or pulverized glass fibres, as described for example in U.S. Pat. No. 5,013,768.
The choice of additive is made depending on the field of application and on properties required for this field. The additives described above are customary in the art and accordingly are added in amounts which are usual in the respective application.
The invention also provides compositions comprising as component (A) at least one ethylenically unsaturated photopolymerizable compound which is emulsified or dissolved in water. Many variants of such radiation-curable aqueous prepolymer dispersions are commercially available. A prepolymer dispersion is understood as being a dispersion of water and at least one prepolymer dispersed therein. The concentration of water in these systems is, for example, from 5 to 80% by weight, in particular from 30 to 60% by weight. The concentration of the radiation-curable prepolymer or prepolymer mixture is, for example, from 95 to 20% by weight, in particular from 70 to 40% by weight. In these compositions the sum of the percentages given for water and prepolymer is in each case 100, with auxiliaries and additives being added in varying quantities depending on the intended use.
The radiation-curable, film-forming prepolymers which are dispersed in water and are often also dissolved are aqueous prepolymer dispersions of mono- or polyfunctional, ethylenically unsaturated prepolymers which are known per se, can be initiated by free radicals and have for example a content of from 0.01 to 1.0 mol of polymerizable double bonds per 100 g of prepolymer and an average molecular weight of, for example, at least 400, in particular from 500 to 10,000. Prepolymers with higher molecular weights, however, may also be considered depending on the intended application. Use is made, for example, of polyesters containing polymerizable Cxe2x80x94C double bonds and having an acid number of not more than 10, of polyethers containing polymerizable Cxe2x80x94C double bonds, of hydroxyl-containing reaction products of a polyepoxide, containing at least two epoxide groups per molecule, with at least one xcex1,xcex2-ethylenically unsaturated carboxylic acid, of polyurethane(meth)acrylates and of acrylic copolymers which contain xcex1,xcex2-ethylenically unsaturated acrylic radicals, as are described in EP 12339. Mixtures of these prepolymers can likewise be used. Also suitable are the polymerizable prepolymers described in EP 33896, which are thioether adducts of polymerizable prepolymers having an average molecular weight of at least 600, a carboxyl group content of from 0.2 to 15% and a content of from 0.01 to 0.8 mol of polymerizable Cxe2x80x94C double bonds per 100 g of prepolymer. Other suitable aqueous dispersions, based on specific alkyl(meth)acrylate polymers, are described in EP 41125, and suitable waterdispersible, radiation-curable prepolymers of urethane. acrylates can be found in DE 2936039.
Further additives which may be included in these radiation-curable aqueous prepolymer dispersions are dispersion auxiliaries, emulsifiers, antioxidants, light stabilizers, dyes, pigments, fillers, for example talc, gypsum, silicic acid, rutile, carbon black, zinc oxide, iron oxides, reaction accelerators, levelling agents, lubricants, wetting agents, thickeners, flatting agents, antifoams and other auxiliaries customary in paint technology. Suitable dispersion auxiliaries are water-soluble organic compounds which are of high molecular mass and contain polar groups, examples being polyvinyl alcohols, polyvinylpyrrolidone or cellulose ethers. Emulsifiers which can be used are nonionic emulsifiers and, if desired, ionic emulsifiers as well.
In certain cases it may be of advantage to use mixtures of two or more of the novel macrophotoinitiators. It is of course also possible to use mixtures with known photoinitiators (C), for example mixtures with benzophenone, benzophenone derivatives, acetophenone, acetophenone derivatives, for example xcex1-hydroxycycloalkyl phenyl ketones or 2-hydroxy-2-methyl-1-phenyl-propanone, dialkoxyacetophenones, xcex1-hydroxy- or xcex1-aminoacetophenones, e.g. (4-methylthiobenzoyl)-1-methyl-1-morpholinoethane, (4-morpholinobenzoyl)-1-benzyl-1-dimethylaminopropane, 4-aroyl-1,3-dioxolanes, benzoin alkyl ethers and benzil ketals, e.g. dimethyl benzil ketal, phenylglyoxalic esters and derivatives thereof, dimeric phenylglyoxalic esters, monoacyl phosphine oxides, e.g. (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, bisacylphosphine oxides, bis(2,6-dimethoxy-benzoyl)-(2,4,4-trimethyl-pentyl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dipentoxyphenylphosphine oxide, trisacylphosphine oxides, ferrocenium compounds, or titanocenes, e.g. bis(cyclopentadienyl)-bis(2,6-difluoro-3-pyrryl-phenyl)titanium.
Where the novel macrophotoinitiators are employed in hybrid systems, use is made, in addition to the novel free-radical hardeners, of cationic photoinitiators, for example peroxide compounds, such as benzoyl peroxide (other suitable peroxides are described in U.S. Pat. No. 4,950,581 column 19, lines 17-25), aromatic sulfonium-, phosphonium- or iodonium salts as described for example in U.S. Pat. No. 4,950,581, column 18, line 60 to column 19, line 10 or cyclopentadienyl-arene-iron(II) complex salts, for example (xcex76-iso-propylbenzene)(xcex75-cyclopentadienyl)iron(II)hexafluorophosphate.
The photopolymerizable compositions generally comprise 0.05 to 15% by weight, preferably 0.1 to 5% by weight, of the macrophotoinitiator, based on the composition. The amount refers to the sum of all photoinitiators added, if mixtures of initiators are employed. Accordingly, the amount either refers to the photoinitiator (B) or the photoinitiators (B)+(C).
In the prior art the most well-known method for preparing block copolymers is anionic polymerization. This method is,however, sensitive against impurities or low polymerization temperature, and it is only suitable for limited kinds of monomers.
Several attempts to prepare block copolymers by means of radical polymerization have been reported. In J. Macromol. Sci. Chem., A28(1), pp. 129-141 (1991) Yagci and his coworkers, for instance, have disclosed the preparation of a block copolymer using an azo compound having photoinitiating groups. These initiators, however, have a poor thermal stability and are explosive due to the azo group. Moreover, the macrophotoinitiators obtained by the described method have broad molecular weight distribution. Popielarz has employed compounds having thermal chain transferring moieties and thermal initiating moieties to prepare a block copolymer. The macrophotoinitiator is prepared by thermally polymerizing a monomer in the presence of a compound which acts as a chain transfer agent. Again azo compounds are employed, which are unstable and explosive. Moreover some of the azo groups even decompose during the preparation of the macrophotoinitiators and lose the property for polymerizing the second monomer.
Block copolymers have not been prepared from macrophotoinitiators which are thermally stable and have a narrow molecular weight distribution so far.
Accordingly, another object of the invention are block copolymers obtained by the photopolymerization of the above described macrophotoinitiators with radically polymerizable monomers. In particular block-copolymers obtained by photopolymerizing monomers of formula XIII and a macrophotoinitiator as described above.
Monomers which are useful for the preparation of the block copolymers are of formula XIII, as described above.
These monomers can be hydrophilic, amphiphilic or hydrophobic.
Examples of hydrophilic monomers are (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-isopropenyl(meth)acrylamide, N-vinylformamide, (meth)acrylic acid, crotonic acid, itaconic acid, cinnamic acid, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, maleic acid, maleic acid anhydride, n-(1,1-dimethyl 3-oxobutyl)(meth)acrylate, 4-hydroxystyrene, 4-hydroxymethyl styrene, p-1-(2-hydroxybutyl)styrene, p-1-(2-hydroxypropyl)styrene, p-2-(2-hydroxypropyl)styrene and styrene sulfonic acid.
Examples of amphiphilic monomers or oligomers are (meth)acrylonitrile, N-(meth)acrylmorpholine, N-vinylpyrrolidone, N-vinylacetamide, N-vinyl-N-methylacetamide, vinyl methyl ether, polyethylene glycol mono-(meth)acrylate, methoxy poly(ethylene glycol)mono-(meth)acrylate, poly(propylene glycol)mono-(meth)acrylate. N-vinylcaprolactam, N-vinylcarbazole, 4-vinylbenzyl tetrahydrofurfuryl ether and glycidyl(meth)acrylate.
Examples of hydrophobic monomers are methyl(meth)acrylate, ethyl(meth)acrylate, n-butyl(meth)acrylate, tert-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isobornyl(meth)acrylate, lauryl(meth)acrylate, stearyl(meth)acrylate, 1-naphtyl(meth)acrylate, 2-naphtyl(meth)acrylate, adamantyl(meth)acrylate, styrene, 2,4,6-trimethystyrene, 2,5-dichlorostyrene, xcex1-methoxystyrene, xcex1-methylstyrene, 3-methylstyrene, 4-methylstyrene, 3-nitrostyrene, 4-chloromethylstyrene, 4-aminostyrene, 4-tert-butylstyrene, 4-tert-butoxycarbonyloxystyrene, 3-bromostyrene, 4-bromostyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 4-cyanostyrene, 4-cyclohexylstyrene, dimethylaminomethyl-styrene, pentachlorostyrene, 4-iodostyrene, xcex2-methoxystyrene, 2-methoxystyrene, 4-methoxystyrene, 1-vinylnaphtalene, 2-vinylnaphtalene, vinyl acetate, vinyl propionate, isobutyl vinyl ether, vinyl chloride, 4-vinylbenzyl chloride, 2-fluoroethyl(meth)acrylate, perfluorocyclohexyl(meth)acrylate, perfluorooctyl(meth)acrylate, 2,2,3,3-tetrafluoropropyl(meth)acrylate, 2,2,2-trifluoroethyl(meth)acrylate and 3-(trifluoromethyl)benzyl(meth)acrylate. The monomers can be used alone or in any desired mixtures.
Preferred block copolymers according to the invention are of formula XV 
wherein
n is 1 or 2;
Ar2 is 
xe2x80x83each of which is unsubstituted or substituted 1 to 5 times by halogen, C1-C12alkyl, C3-C12alkenyl, C5-C6cycloalkyl, phenyl-C1-C3alkyl, xe2x80x94COOH, xe2x80x94COO(C1-C4alkyl), xe2x80x94OR7, xe2x80x94SR8, xe2x80x94SOR8, xe2x80x94SO2R8, xe2x80x94CN, xe2x80x94SO2NH2, xe2x80x94SO2NH(C1-C4alkyl), xe2x80x94SO2xe2x80x94N(C1-C4alkyl)2, xe2x80x94NR9R10, xe2x80x94NHCOR9, or by a group of formula IV 
or Ar2 is a group of formula Va or VIa 
G is unbranched or branched C1-C7alkylene;
L and E independently of one another are a direct bond, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94, provided that L and E are not both a direct bond simultaneously;
R1 and R2 independently of one another are R7Oxe2x80x94, C1-C8alkyl, which is unsubstituted or substituted by OH, C1-C4alkoxy, SR8, CN, (C1-C8alkyl)O(CO)xe2x80x94, (C1-C4alkyl)-(OC)Oxe2x80x94 or xe2x80x94N(R3)(R4), or R1 and R2 independently of one another are C3-C6alkenyl, phenyl, chlorophenyl, R7xe2x80x94O-phenyl, R8xe2x80x94S-phenyl or phenyl-C1-C3-alkyl, or R1 and R2 together are unbranched or branched C2-C9alkylene, C3-C9oxaalkylene or C3-C9azaalkylene, or R1 and R2 independently of one another are a radical of formula VII or VIII 
p is 0 or 1;
Ar3 is phenyl, naphthyl, furyl, thienyl or pyridiyl, each of which is unsubstituted or substituted by halogen, SH, OH, C1-C12alkyl, OH-substituted C1-C4alkyl, halogen-substituted C1-C4alkyl, SH-substituted C1-C4alkyl, N(R17)2-substituted C1-C4alkyl, C1-C12alkoxy-substituted C1-C4alkyl, (C1-C18alkyl)O(OC)-substituted C1-C4alkyl, CH3O(CH2CH2O)mCO-substituted C1-C4alkyl, (C1-C4alkyl)(OC)O-substituted C1-C4alkyl, C1-C12alkoxy, (C1-C18alkyl)(OC)O-substituted C1-C4alkoxy, CH3O(CH2CH2O)mCO-substituted C1-C4alkoxy, xe2x80x94(OCH2CH2)mOH, xe2x80x94(OCH2CH2)mOCH3, C1-C8alkylthio, phenoxy, xe2x80x94COO(C1-C18alkyl), xe2x80x94CO(OCH2CH2)mOCH3, phenyl or benzoyl;
m is 1 to 20;
R3 is hydrogen, C1-C12alkyl, C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R3 is C3-C5alkenyl, C5-C12-cycloalkyl or phenyl-C1-C3alkyl;
R4 is C1-C12alkyl; C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R4 is C3-C5alkenyl, C5-C12-cycloalkyl, phenyl-C1-C3alkyl; phenyl which is unsubstituted or substituted by halogen, C1-C12alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl);
or R4 together with R2 is C1-C7alkylene, phenyl-C1-C4alkylene, o-xylylene, 2-butenylene, C2-C3oxaalkylene or C2-C3azaalkylene;
or R3 and R4 together are C3-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94 and which C3-C7alkylene is unsubstituted or substituted by OH, SH, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl);
R6 is hydrogen, C1-C12alkyl, OH-substituted C1-C12alkyl, SH-substituted C1-C12alkyl or HSxe2x80x94(CH2), xe2x80x94COO-substituted C1-C12alkyl; C2-C12alkyl, which is interrupted by xe2x80x94Oxe2x80x94, xe2x80x94NHxe2x80x94 or xe2x80x94Sxe2x80x94; or R6 is C3-C5alkenyl, phenyl-C1-C3-alkyl, xe2x80x94CH2CH2CN, C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, OH-substituted C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, SH-substituted C1-C4alkyl-COxe2x80x94CH2CH2xe2x80x94, C2-C8alkanoyl, OH-substituted C2-C8alkanoyl, SH-substituted C2-C8alkanoyl or benzoyl;
R7 is hydrogen, C1-C12alkyl, C3-C12-alkenyl, cyclohexyl, hydroxycyclohexyl; C1-C4alkyl, which is mono- or polysubstituted by Cl, Br, CN, SH, xe2x80x94N(C1-C4alkyl)2, piperidinyl, morpholinyl, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C4alkyl)2, 
xe2x80x83xe2x80x94CO(C1-C4alkyl) or by 
xe2x80x83or R7 is 2,3-epoxypropyl, xe2x80x94(CH2CH2O)nH; phenyl which is unsubstituted or substituted by halogen, C1-C4alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl); or R7 is phenyl-C1-C3-alkyl, tetrahydropyranyl, tetrahydrofuranyl, xe2x80x94COOR,19, xe2x80x94COO(C1-C8alkyl), xe2x80x94CONH(C1-C4alkyl), xe2x80x94CON(C1-C8alkyl)2, xe2x80x94Si(R20)(R21)2, or xe2x80x94SO2R22;
R8 is hydrogen, C1-C12alkyl, C3-C12alkenyl, cyclohexyl, hydroxycyclohexyl; C1-C4alkyl, which is mono- or polysubstituted by Cl, Br, CN, SH, xe2x80x94N(C1-C4alkyl)2, piperidinyl, morpholinyl, OH, C1-C4alkoxy, xe2x80x94OCH2CH2CN, xe2x80x94OCH2CH2COO(C1-C4alkyl), xe2x80x94O(CO)R19, xe2x80x94COOH, xe2x80x94COO(C1-C8-alkyl), xe2x80x94CON(C1-C4alkyl)2, 
xe2x80x83xe2x80x94CO(C1-C4alkyl) or 
xe2x80x83or R8 is 2,3-epoxypropyl, phenyl-C114 C3alkyl, phenyl-C1-C3hydroxyalkyl; phenyl which is unsubstituted or mono- or poly-substituted by halogen, SH, C1-C4alkyl, C1-C4alkoxy or xe2x80x94COO(C1-C4alkyl); or
R8 is 2-benzothiazyl, 2-benzimidazolyl, xe2x80x94CH2CH2xe2x80x94Oxe2x80x94CH2CH2xe2x80x94SH or xe2x80x94CH2CH2xe2x80x94Sxe2x80x94CH2CH2xe2x80x94SH;
R9 and R10 independently of one another are hydrogen, C1-C12alkyl; C2-C4alkyl, which is substituted by OH, SH, C1-C4alkoxy, CN or xe2x80x94COO(C1-C4alkyl); or R9 and R10 independently of one another are C3-C5alkenyl, cyclohexyl, phenyl-C1-C3alkyl; phenyl which is unsubstituted or mono- or poly-substituted by C1-C12alkyl or halogen; or R9 and R10 together are C2-C7alkylene, optionally interrupted by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
R11 and R12 independently of one another are a direct bond, xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COxe2x80x94 or xe2x80x94N(R6)xe2x80x94; provided that R11 and R12 are not a direct bond simultaneously;
R13 is hydrogen, C1-C8alkyl or phenyl;
R14, R15 and R16 independently of one another are hydrogen or C1-C4alkyl;
R17 is hydrogen, C1-C8alkyl or phenyl;
R19 is C1-C4alkyl, C2-C4alkenyl or phenyl;
R20 and R21 independently of one another are C1-C4alkyl or phenyl;
R22 is C1-C18alkyl; or phenyl which is unsubstituted or substituted by C1-C14alkyl;
A1 is a direct bond, xe2x80x94X[(CH2)lXxe2x80x2]qxe2x80x94[(C6H4)oXxe2x80x3]rxe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
X, Xxe2x80x2 and Xxe2x80x3 independently of each other are a direct bond, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94N(R6)xe2x80x94, xe2x80x94O(CO)xe2x80x94, xe2x80x94COOxe2x80x94 xe2x80x94NHCOxe2x80x94, xe2x80x94CONHxe2x80x94 or xe2x80x94COxe2x80x94;
l is an integer from 0 to 10;
q is an integer from 0 to 5;
o and r independently of one another are an integer 0, 1 or 2;
CT1 is xe2x80x94Yxe2x80x2xe2x80x94, xe2x80x94R25xe2x80x94, 
Zxe2x80x2 is xe2x80x94COOR25xe2x80x94, xe2x80x94CONR9R25xe2x80x94, or xe2x80x94Ar2xe2x80x94;
Yxe2x80x2 is xe2x80x94W(R8)tR25xe2x80x94;
t is an integer 0, 1 or 2;
W is S, Si, Se, P, Br, Cl, Sn, xe2x80x94Oxe2x80x94Oxe2x80x94, S(xe2x95x90O), S(xe2x95x90O)2, or P(xe2x95x90O);
R23 and R24 independently of one another are hydrogen, or C1-C8alkyl; or R23 and R24 together are C5-C7cyloalkyl; and
R25 is a direct bond, C1-C4alkylene or phenylene.
u is 0 or 1; and
J and J1 independently of one another are a polymeric group, provided that J and J1 are not simultaneously the same groups.
Further preferred block copolymers are such, wherein formula XV
Ar2 is 
xe2x80x83which is unsubstituted or substituted 1 to 4 times by halogen, C1-C12alkyl
or xe2x80x94OR7;
R7 is hydrogen or C1-C12alkyl;
X, Xxe2x80x2 and Xxe2x80x3 independently of each other are a direct bond, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94N(R6)xe2x80x94;
R6 is hydrogen or C1-C12alkyl;
l is an integer from 0 to 4;
q is an integer from 0 or 1;
o and r independently of one another are an integer 0, 1 or 2;
CT1 is xe2x80x94Yxe2x80x2xe2x80x94 or 
Zxe2x80x2 is xe2x80x94COOR25xe2x80x94 or xe2x80x94CONR9R25xe2x80x94;
t and u are 0;
W is S;
R8 and R9 independently of one another are hydrogen or C1-C12alkyl;
R23 and R24 are hydrogen; and
R25 is a direct bond or C1-C4alkylene.
Accordingly, for example, the following block-copolymers are obtained: polystyrene-block-polybutadiene, polystyrene-block-polyisobutene, polybutadiene-block-poly(tert-butyl methacrylate) or polyisoprene block-poly(tert-butyl methacrylate), which, for example can be employed as lubricant or oil; poly(ethylhexyl methacrylate)-block-poly(methacrylic acid), which can be employed, for example, as a pigment dispersant or an emulsion stabilizer; polystyrene-block-polybutadiene, polystyrene-block-poly(methyl acrylate), (polyacrylo-nitrile-random-polystyrene)-block-(polystyrene-random-polybutadiene), polybutadiene-block-poly(dimethyl itaconate), which, for example, can be employed as thermoplastic elastomers; polystyrene-block-poly(vinyl acetate), poly(methyl methacrylate)-block-poly(vinyl acetate), which, for example, can be employed as polymeric additive for polyester resin FRP molding; {poly(butyl methacrylate)-random-poly(methyl methacrylate)}-block-poly(perfluoroethyl acrylate), polystyrene-block-poly(hydroxylethyl methacrylate), which can be employed, for example, as surface treatment reagent; polystyrene-block-poly(tert-butyl methacrylate), polystyrene-block-poly(methyl methacrylate), polystyrene-block-poly(tert-butyl acrylate), polystyrene-block-poly(4-vinylpyridine), polystyrene-block-poly(2-vinylpyridine), polystyrene-block-poly(tert-butylstyrene), polybutadiene-block-poly(methyl methacrylate), polyisoprene-block-poly(methyl methacrylate), polybutadiene-block-poly(tert-butyl acrylate), polyisoprene-block-poly(tert-butyl acrylate), poly(methyl methacrylate)-block-poly(tert-butyl methacrylate), poly(methyl methacrylate)-block-poly(tert-butyl acrylate), poly(methyl methacrylate)-block-poly(2-vinylpyridine), poly(methyl methacrylate)-block-poly(4-vinylpyridine), poly(tert-butyl methacrylate)-block-poly(tert-butyl methacrylate)-block-poly(tert-butyl acrylate), poly(tert-butyl acrylate)-block-poly(2-vinylpyridine), poly(tert-butyl acrylate)-block-poly(4-vinylpyridine), poly(2-vinylpyridine)-block-poly(4-vinylpyridine), and so on.
Examples for amphiphilic block copolymers are polystyrene-block-poly(sodium methacrylate), polystyrene-block-poly(sodium acrylate), polystyrene-block-poly(methacrylic acid), polystyrene-block-poly(acrylic acid), polystyrene-block-poly(N-methyl-4-vinylpyridinium iodide), polystyrene-block-poly(N-methyl-2-vinylpyridinium iodide), polystyrene-block-poly(2-hydroxyethyl acrylate), polystyrene-block-poly(2-hydroxyethyl methacrylate), polystyrene-block-poly(2-hydroxyethyl acrylate), polystyrene-block-poly(2-hydroxyethyl methacrylate), polyisoprene-block-poly(sodium methacrylate), polyisoprene-block-poly(sodium acrylate), polyisoprene-block-poly(methacrylic acid), polyisoprene-block-poly(acrylic acid), polyisoprene-block-poly(N-methyl-4-vinylpyridinium iodide), polyisoprene-block-poly(N-methyl-2-vinylpyridinium iodide), polyisoprene-block-poly(2-hydroxyethyl acrylate), polyisoprene-block-poly(2-hydroxyethyl methacrylate), polyisoprene-block-poly(2-hydroxyethyl acrylate), polybutadiene-block-poly(2-hydroxyethyl methacrylate), polybutadiene-block-poly(sodium methacrylate), polybutadiene-block-poly(sodium acrylate), polybutadiene-block-poly(methacrylic acid), polybutadiene-block-poly(acrylic acid), polybutadiene-block-poly(N-methyl-4-vinylpyridinium iodide), polybutadiene-block-poly(N-methyl-2-vinylpyridinium iodide), polybutadiene-block-poly(2-hydroxyethyl acrylate), polybutadiene-block-poly(2-hydroxyethyl methacrylate), polybutadiene-block-poly(2-hydroxyethyl acrylate), polybutadiene-block-poly(2-hydroxyethyl methacrylate), poly(methyl methacrylate)-block-poly(2-hydroxyethyl methacrylate), poly(methyl methacrylate)-block-poly(sodium methacrylate), poly(methyl methacrylate)-block-poly(sodium acrylate), poly(methyl methacrylate)-block-poly(methacrylic acid), poly(methyl methacrylate)-block-poly(acrylic acid), poly(methyl methacrylate)-block-poly(N-methyl-4-vinylpyridinium iodide), poly(methyl methacrylate)-block-poly(N-methyl-2-vinylpyridinium iodide), poly(methyl methacrylate)-block-poly(2-hydroxyethyl acrylate), poly(methyl methacrylate)-block-poly(2-hydroxyethyl methacrylate), poly(methyl methacrylate)-block-poly(2-hydroxyethyl acrylate), poly(methyl methacrylate)-block-poly(2-hydroxyethyl methacrylate), poly(tert-butyl methacrylate)-block-poly(2-hydroxyethyl methacrylate), poly(tert-butyl methacrylate)-block-poly(sodium methacrylate), poly(tert-butyl methacrylate)-block-poly(sodium acrylate), poly(tert-butyl methacrylate)-block-poly(methacrylic acid), poly(tert-butyl methacrylate)-block-poly(acrylic acid), poly(tert-butyl methacrylate)-block-poly(N-methyl-4-vinylpyridinium iodide), poly(tert-butyl methacrylate)-block-poly(N-methyl-2-vinylpyridinium iodide), poly(tert-butyl methacrylate)-block-poly(2-hydroxyethyl acrylate), poly(tert-butyl methacrylate)-block-poly(2-hydroxyethyl methacrylate), poly(tert-butyl methacrylate)-block-poly(2-hydroxyethyl acrylate), poly(tert-butyl methacrylate)-block-poly(2-hydroxyethyl methacrylate), poly(ethylhexyl methacrylate)-block-poly(acrylic acid), poly(ethylhexyl acrylate)-block-poly(methacrylic acid), poly(ethylhexyl acrylate)-block-poly(acrylic acid).
Subject of the invention also is a process for preparing a block copolymer of formula XV, characterized in that a macrophotoinitiator as descsribed above and at least one radically polymerizable monomer are mixed and irradiated with light.
The photopolymerization can be carried out in bulk or in any solution at any concentration. Examples of suitable solvents are hydrocarbons such as benzene, toluene, xylene, cyclohexane; esters such as ethyl acetate, butyl acetate, amyl acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol, ethanol, isobutyl alcohol 1,2,6-hexanetriol glycerin; amides such as N,N-dimethylformamide, N-methylformamide, N,N-diethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide; pyrrolidones such as 1-methyl-2-pyrrolidone, pyrrolidone xcex5-caprolactam; glycols such as ethylene glycol, propylene glycol, butylene glycol, tri(methylene glycol), tri(ethylene glycol), hexylene glycol, di(ethylene glycol), diethylene glycol, di(propylene glycol), poly(ethylene glycol); glycol ethers such as 2-methoxyethanol, 2-ethoxyethanol, 2-(2-methoxy)ethoxy ethanol, 2-propoxyethanol, 2-butoxyethanol, di(ethylene glycol)monomethyl ether, di(ethylene glycol)monoethyl ether, di(ethylene glycol)monobutyl ether, tri(ethylene glycol)monoethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, di(propylene glycol)monomethyl ether, di(propylene glycol)monoethyl ether, tri(propylene glycol)monomethyl ether, 3-methoxyl-3-methyl-1-butanol; halogenated hydrocarbon, such as chloroform or methylene chloride. The solvent may also be in the form of a mixture of two or more of the above-mentioned solvents.
It is appropriate to conduct the polymerization in an inert atmosphere in order to avoid inactivation of the generated radicals. Examples of suitable inert gases are nitrogen, helium, neon, argon and xenon.
The polymerization usually is conducted at an appropriate temperature at which the monomers can be polymerized. The temperature strongly depends on the choice of the monomer and solvent. It should be higher than the melting point of the employed monomers and solvents and lower than the boiling point of them. The temperature is generally in the range from xe2x88x9240xc2x0 C. to 180xc2x0 C., preferably from 0xc2x0 C. to 100xc2x0 C.
The photopolymerization can also be conducted according to the method described in WO 98/37105 in order to prepare oligomers having a specific molecular weight.
The number and weight average molecular weights of the obtained block copolymers can be determined by a common method such as GPC measurement calibrated by the standard styrene or/and methacrylate and are in the range from 300 to 10,000,000, preferably from 500 to 1,000,000.
Block copolymers generally are useful for various applications and also the block-copolymers according to the invention can be employed for various purposes.
Polystyrene-block-polybutadiene or polystyrene-block-polyisobutene can, for example, be a key component for xe2x80x9clow temperature adhesives for photographic materialsxe2x80x9d as disclosed in U.S. Pat. No. 4,126,464.
Poly(tert-butyl methacrylate)-block-polybutadiene or poly(tert-butyl methacrylate)-block-polyisoprene, for instance, can be employed as lubricant as disclosed in U.S. Pat. No. 5,002,676.
Amphiphilic block copolymers, especially poly(hydroxyhexyl methacrylate)-block-{poly(methyl methacrylate)-random-poly(acrylic acid)} or poly(hydroxyhexyl methacrylate)-block-poly(methyl methacrylate), are for example employed as bio-compatible polymers for medical materials, as is decribed in JP 3-223377 A.
Polystyrene-block-polydiene, especially polystyrene-block-polybutadiene and polystyrene-block-polyisoprene, can be used as a material for an imageable resist composition as is for example disclosed in U.S. Pat. No. 5,318,877.
Poly(ethylhexyl methacrylate)-block-poly(methacrylic acid) exhibits a very good pigment dispersibility and emulsion stability, as is described in an article in Progress in Organic Coating 27(1996), 255-260.
According to Ueda, Kagaku To Kogyo [Chemical Industry Japan], 70(5), 184-190, the following block copolymers are suitable for many proposes, for instance as thermoplastic elastomers: polystyrene-block-polybutadiene, poly(methyl acrylate)-block-polystyrene, (polyacrylonitrile-random-polystyrene)-block-(polystyrene-random-polybutadiene), poly(dimethyl itaconate)-block-polybutadiene; as polymeric additives for polyester resin FRP molding: polystyrene-block-poly(vinyl acetate), poly(methyl methacrylate)-block-poly(vinyl acetate); as surface treatment reagent: {poly(butyl methacrylate)-random-poly(methyl methacrylate)}-block-poly(perfluoroethyl acrylate), poly(hydroxylethyl methacrylate)-block-polystyrene.
Accordingly, subject of the invention is the use of block copolymers according to the present invention for the preparation of pigment dispersants, emulsion stabilizers, plastic elastomers, antishrinking agents, coatings, powder coatings, medical materials, imaging materials, thermal transfer imaging resins; for the preparation of tackfiers for adhesives, base resins for hot melt adhesives, pressure sensitive adhesives, or solvent applied adhesives, laminating adhesives for glass, adhesives for adhering a polymer; for the preparation of oil additives for smoke suppression, viscositiy modifiers for lubricating oils, pour point depressants for fuels or oils; for the preparation of modifiers for asphalt, wire insulations or jacketing, tougheners for polyolefines, drip suppressants for synthetic polymers, additives for wax candles for smoke suppression or drip control, blown or cast films or sheets, foamed objects, hoses, non-woven fabrics, roofing membranes, tougheners for thermoplastics or thermosets, internal plasticizers for polymers, capliner resins, fine denier fibres, compatibilizing agents, flexible pouches, wrap packaging films, as base for synthetic lubricants; as base polymer for caulking; as base resin for carpet backings, as additive to thermoplastic polymers to improve the adhesion of paint thereto, or as antifogging agents.
Such applications are, for example, described in U.S. Pat. No. 5,880,241.
To perform the photopolymerization, either of the novel compositions (comprising a macrophotoinitiator and a radically polymerizable monomer) or to perform the photopolymerisation for the prepapration of the block-copolymers according to the invention suitable radiation is present, for example, in sunlight or light from artificial light sources. Consequently, a large number of very different types of light sources are employed. Both point sources and arrays (xe2x80x9clamp carpetsxe2x80x9d) are suitable. Examples are carbon arc lamps, xenon arc lamps, medium-pressure, high-pressure and low-pressure mercury lamps, possibly with metal halide dopes (metal-halogen lamps), microwave-stimulated metal vapour lamps, excimer lamps, superactinic fluorescent tubes, fluorescent lamps, argon incandescent lamps, electronic flashlights, photographic flood lamps, light emitting diodes (LED), electron beams and X-rays. The distance between the lamp and the substrate to be exposed in accordance with the invention may vary depending on the intended application and the type and output of lamp, and may be, for example, from 2 cm to 150 cm. Laser light sources, for example excimer lasers, such as KrF lasers for exposure at 248 nm or ArF lasers are also suitable. Lasers in the visible region can also be employed. By this method it is possible to produce printed circuits in the electronics industry, lithographic offset printing plates or relief printing plates, and also photographic image recording materials.
The photopolymerizable compositions as well as the block copolymers according to the invention can be used for various purposes, for example as printing ink, as a clear finish, as a white finish, for example for wood or metal, as powder coating, as a coating material, inter alia for paper, wood, metal or plastic, as a daylight-curable coating for the marking of buildings and roadmarking, for photographic reproduction techniques, for holographic recording materials, for image recording techniques or to produce printing plates which can be developed with organic solvents or with aqueous alkalis, for producing masks for screen printing, as dental filling compositions, as adhesives, as pressure-sensitive adhesives, as laminating resins, as etch resists or permanent resists, and as solder masks for electronic circuits, for producing three-dimensional articles by mass curing (UV curing in transparent moulds) or by the stereolithography technique, as is described, for example, in U.S. Pat. No. 4,575,330, to produce composite materials (for example styrenic polyesters, which may, if desired, contain glass fibres and/or other fibres and other auxiliaries) and other thick-layered compositions, for coating or sealing electronic components and chips, or as coatings for optical fibres.
The compositions according to the invention are further suitable for the production of medical equipment (e.g. contact lenses), auxiliaries or implants.
Further the compositions according to the invention are suitable for the preparation of gels with thermotropic properties, as for example described in DE 19700064 and EP 678534.
Accordingly, a further subject of the invention is the use of a macrophotoinitiator according to the invention for producing pigmented and non-pigmented paints and varnishes, for producing clear and pigmented aqueous dispersions, powder coatings, printing inks, printing plates, adhesives, dental filling compositions, wave-guides, optical switches, color proofing systems, glass fiber cable coatings, screen printing stencils, resist materials, composite compositions, for photographic reproductions, for producing masks for screen printing, for photoresists for printed electronic circuits, for encapsulating electrical and electronic components, for producing magnetic recording materials, for producing three-dimensional objects by means of stereolithography or bulk-curing, and as image recording material, especially for holographic recording.
The novel macrophotoinitiators may additionally be employed as initiators for emulsion polymerizations, pearl polymerizations or suspension polymerizations, as polymerization initiators for fixing ordered states of liquid-crystalline monomers and oligomers, or as initiators for fixing dyes on organic materials.
In coating materials, use is frequently made of mixtures of a prepolymer with polyunsaturated monomers, which may additionally include a monounsaturated monomer as well. It is the prepolymer here which primarily dictates the properties of the coating film, and by varying it the skilled worker is able to influence the properties of the cured film. The polyunsaturated monomer functions as a crosslinking agent which renders the film insoluble. The monounsaturated monomer functions as a reactive diluent, which is used to reduce the viscosity without the need to employ a solvent.
Unsaturated polyester resins are usually used in two-component systems together with a monounsaturated monomer, preferably with styrene. For photoresists, specific one-component systems are often used, for example polymaleimides, polychalcones or polyimides, as described in DE 2308830.
The novel macrophotoinitiator can also be used for the polymerization of radiation-curable powder coatings. The powder coatings can be based on solid resins and monomers containing reactive double bonds, for example maleates, vinyl ethers, acrylates, acrylamides and mixtures thereof. A free-radically UV-curable powder coating can be formulated by mixing unsaturated polyester resins with solid acrylamides (for example methyl methylacrylamidoglycolate) and a photoinitiator according to the invention, similar formulations being described, for example, in the paper xe2x80x9cRadiation Curing of Powder Coatingxe2x80x9d, Conference Proceedings, Radtech Europe 1993 by M. Wittig and Th. Gohmann. The powder coatings can also contain binders, as are described, for example, in DE 4228514 and in EP 636669. Free-radically UV-curable powder coatings can also be formulated by mixing unsaturated polyester resins with solid acrylates, methacrylates or vinyl ethers and with a novel photoinitiator (or photoinitiator mixture). The powder coatings may also comprise binders as are described, for example, in DE 4228514 and in EP 636669. The UV-curable powder coatings may additionally comprise white or coloured pigments. For example, preferably rutile titanium dioxide can be employed in concentrations of up to 50% by weight in order to give a cured powder coating of good hiding power. The procedure normally comprises electrostatic or tribostatic spraying of the powder onto the substrate, for example metal or wood, melting of the powder by heating, and, after a smooth film has formed, radiation-curing of the coating with ultraviolet and/or visible light, using for example medium-pressure mercury lamps, metal halide lamps or xenon lamps. A particular advantage of the radiation-curable powder coatings over their heat-curable counterparts is that the flow time after melting the powder particles can be delayed in order to ensure the formation of a smooth, high-gloss coating. In contrast to heat-curable systems, radiation-curable powder coatings can be formulated to melt at lower temperatures without the unwanted effect of shortening their lifetime. For this reason, they are also suitable as coatings for heat-sensitive substrates, for example wood or plastics.
In addition to the novel photoinitiator the powder coating formulations may also include UV absorbers. Appropriate examples are listed above in sections 1.-8.
The novel photocurable compositions are suitable, for example, as coating materials for substrates of all kinds, for example wood, textiles, paper, ceramics; glass, plastics such as polyesters, polyethylene terephthalate, polyolefins or cellulose acetate, especially in the form of films, and also metals such as Al, Cu, Ni, Fe, Zn, Mg or Co and GaAs, Si or SiO2 to which it is intended to apply a protective layer or, by means of imagewise exposure, to generate an image.
Coating of the substrates can be carried out by applying to the substrate a liquid composition, a solution or a suspension. The choice of solvents and the concentration depend principally on the type of composition and on the coating technique. The solvent should be inert, i.e. it should not undergo a chemical reaction with the components and should be able to be removed again, after coating, in the course of drying. Examples of suitable solvents are ketones, ethers and esters, such as methyl ethyl ketone, isobutyl methyl ketone, cyclopentanone, cyclohexanone, N-methylpyrrolidone, dioxane, tetrahydrofuran, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 1,2-dimethoxyethane, ethyl acetate, n-butyl acetate and ethyl 3-ethoxypropionate.
The solution is applied uniformly to a substrate by means of known coating techniques, for example by spin coating, dip coating, knife coating, curtain coating, brushing, spraying, especially by electrostatic spraying, and reverse-roll coating, and also by means of electrophoretic deposition. It is also possible to apply the photosensitive layer to a temporary, flexible support and then to coat the final substrate, for example a copper-clad circuit board, by transferring the layer via lamination.
The quantity applied (coat thickness) and the nature of the substrate (layer support) are dependent on the desired field of application. The range of coat thicknesses generally comprises values from about 0.1 xcexcm to more than 100 xcexcm, for example 20 mm or 0.02 to 10 cm, preferably 0.02 to 2 cm.
The invention therefore also pertains to a substrate coated with a photopolymerizable composition as described above.
The novel radiation-sensitive compositions further find application as negative resists, having a very high sensitivity to light and being able to be developed in an aqueous alkaline medium without swelling. They are suitable as photoresists for electronics (electroplating resist, etch resist, solder resist), the production of printing plates, such as offset printing plates or screen printing plates, for the production of printing formes for relief printing, planographic printing, rotogravure or of screen printing formes, for the production of relief copies, for example for the production of texts in braille, for the production of stamps, for use in chemical milling or as a microresist in the production of integrated circuits. The possible layer supports, and the processing conditions of the coating substrates, are just as varied.
The compositions according to the invention also find application for the production of one- or more-layered materials for the image recording or image reproduction (copies, reprography), which may be uni- or polychromatic. Furthermore the materials are suitable for colour proofing systems. In this technology formulations containing microcapsules can be applied and for the image production the radiation curing can be followed by a thermal treatment. Such systems and technologies and their applications are for example disclosed in U.S. Pat. No. 5,376,459.
Substrates used for photographic information recordings include, for example, films of polyester, cellulose acetate or polymer-coated papers; substrates for offset printing formes are specially treated aluminium, substrates for producing printed circuits are copper-clad laminates, and substrates for producing integrated circuits are silicon wafers. The layer thicknesses for photographic materials and offset printing formes is generally from about 0.5 xcexcm to 10 xcexcm, while for printed circuits it is from 1.0 xcexcm to about 100 xcexcm.
Following the coating of the substrates, the solvent is removed, generally by drying, to leave a coat of the photo resist on the substrate.
The term xe2x80x9cimagewisexe2x80x9d exposure includes both, exposure through a photomask comprising a predetermined pattern, for example a slide, as well as exposure by means of a laser or light beam, which for example is moved under computer control over the surface of the coated substrate and in this way produces an image, and irradiation with computer-controlled electron beams. It is also possible to use masks made of liquid crystals that can be adressed pixel by pixel to generate digital images, as is, for example, described by A. Bertsch, J. Y. Jezequel, J. C. Andre in Journal of Photochemistry and Photobiology A: Chemistry 1997, 107, p. 275-281 and by K.-P. Nicolay in Offset Printing 1997, 6, p. 34-37.
Following the imagewise exposure of the material and prior to development, it may be advantageous to carry out thermal treatment for a short time. In this case only the exposed sections are thermally cured. The temperatures employed are generally 50-150xc2x0 C., preferably 80-130xc2x0 C.; the period of thermal treatment is in general between 0.25 and 10 minutes. The photopolymerizable composition comprising the macrophotoinitiator, as well as the block copolymers according to the invention can be used in color filter (color mosaique) resists.
The photocurable composition may additionally be used in a process for producing printing plates or photoresists as is described, for example, in DE 4013358. In such a process the composition is exposed for a short time to visible light with a wavelength of at least 400 nm, without a mask, prior to, simultaneously with or following imagewise irradiation.
After the exposure and, if implemented, thermal treatment, the unexposed areas of the photosensitive coating are removed with a developer in a manner known per se.
As already mentioned, the novel compositions can be developed by aqueous alkalis. Particularly suitable aqueous-alkaline developer solutions are aqueous solutions of tetraalkylammonium hydroxides or of alkali metal silicates, phosphates, hydroxides and carbonates. Minor quantities of wetting agents and/or organic solvents may also be added, if desired, to these solutions. Examples of typical organic solvents, which may be added to the developer liquids in small quantities, are cyclohexanone, 2-ethoxyethanol, toluene, acetone and mixtures of such solvents.
Photocuring is of great importance for printings, since the drying time of the ink is a critical factor for the production rate of graphic products, and should be in the order of fractions of seconds. UV-curable inks are particularly important for screen printing and offset inks.
As already mentioned above, the novel compositions are suitable for producing printing plates. This application uses, for example, mixtures of soluble linear polyamides or styrene/butadiene and/or styrene/isoprene rubber, polyacrylates or polymethyl methacrylates containing carboxyl groups, polyvinyl alcohols or urethane acrylates with photopolymerizable monomers, for example acrylamides and/or methacrylamides, or acrylates and/or methacrylates, and a photoinitiator. Films and plates of these systems (wet or dry) are exposed over the negative (or positive) of the printed original, and the uncured parts are subsequently washed out using an appropriate solvent or aqueos solutions.
Another field where photocuring is employed is the coating of metals, in the case, for example, of the coating of metal plates and tubes, cans or bottle caps, and the photocuring of polymer coatings, for example of floor or wall coverings based on PVC. Examples of the photocuring of paper coatings are the colourless varnishing of labels, record sleeves and book covers.
Also of interest is the use of the novel compounds and photoinitiator systems for curing shaped articles made from composite compositions. The composite compound consists of a self-supporting matrix material, for example a glass fibre fabric, or alternatively, for example, plant fibres [cf. K.-P. Mieck, T. Reussmann in Kunststoffe 85 (1995), 366-370], which is impregnated with the photocuring formulation. Shaped parts comprising composite compounds, when produced using the novel compounds, attain a high level of mechanical stability and resistance. The novel compounds can also be employed as photocuring agents in moulding, impregnating and coating compositions as are described, for example, in EP 7086. Examples of such compositions are gel coat resins, which are subject to stringent requirements regarding curing activity and yellowing resistance, and fibre-reinforced mouldings, for example, light diffusing panels which are planar or have lengthwise or crosswise corrugation. Techniques for producing such mouldings, such as hand lay-up, spray lay-up, centrifugal casting or filament winding, are described, for example, by P. H. Selden in xe2x80x9cGlasfaserverstxc3xa4rkte Kunststoffexe2x80x9d, [glass fiber-enforced plastics] page 610, Springer Veriag Berlin-Heidelberg-New York 1967. Examples of articles which can be produced by these techniques are boats, fibre board or chipboard panels with a double-sided coating of glass fibre-reinforced plastic, pipes, containers, etc. Further examples of moulding, impregnating and coating compositions are UP resin gel coats for mouldings containing glass fibres (GRP), such as corrugated sheets and paper laminates. Paper laminates may be based on urea resins or melamine resins. Prior to production of the laminate, the gel coat is produced on a support (for example a film). The novel photocurable compositions can also be used for casting resins or for embedding articles, for example electronic components, etc. Curing usually is carried out using medium-pressure mercury lamps as are conventional in UV curing. However, there is also interest in less intense lamps, for example of the type TL 40W/03 or TL40W/05. The intensity of these lamps corresponds approximately to that of sunlight. It is also possible to use direct sunlight for curing. A further advantage is that the composite composition can be removed from the light source in a partly cured, plastic state and can be shaped, with full curing taking place subsequently.
The compositions and compounds according to the invention can be used for the production of holographies, waveguides, optical switches wherein advantage is taken of the development of a difference in the index of refraction between irradiated and unirradiated areas.
The use of photocurable compositions for imaging techniques and for the optical production of information carriers is also important. In such applications, as already described above, the layer (wet or dry) applied to the support is irradiated imagewise, e.g. through a photomask, with UV or visible light, and the unexposed areas of the layer are removed by treatment with a developer. Application of the photocurable layer to metal can also be carried out by electrodeposition. The exposed areas are polymeric through crosslinking and are therefore insoluble and remain on the support. Appropriate colouration produces visible images. Where the support is a metallized layer, the metal can, following exposure and development, be etched away at the unexposed areas or reinforced by electroplating. In this way it is possible to produce electronic circuits and photoresists.